drivers/video/udlfb.c

   1 /*
   2  * udlfb.c -- Framebuffer driver for DisplayLink USB controller
   3  *
   4  * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
   5  * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
   6  * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License v2. See the file COPYING in the main directory of this archive for
  10  * more details.
  11  *
  12  * Layout is based on skeletonfb by James Simmons and Geert Uytterhoeven,
  13  * usb-skeleton by GregKH.
  14  *
  15  * Device-specific portions based on information from Displaylink, with work
  16  * from Florian Echtler, Henrik Bjerregaard Pedersen, and others.
  17  */
  18
  19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/usb.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/mm.h>
  27 #include <linux/fb.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/slab.h>
  30 #include <linux/prefetch.h>
  31 #include <linux/delay.h>
  32 #include <video/udlfb.h>
  33 #include "edid.h"
  34
  35 static struct fb_fix_screeninfo dlfb_fix = {
  36         .id =           "udlfb",
  37         .type =         FB_TYPE_PACKED_PIXELS,
  38         .visual =       FB_VISUAL_TRUECOLOR,
  39         .xpanstep =     0,
  40         .ypanstep =     0,
  41         .ywrapstep =    0,
  42         .accel =        FB_ACCEL_NONE,
  43 };
  44
  45 static const u32 udlfb_info_flags = FBINFO_DEFAULT | FBINFO_READS_FAST |
  46                 FBINFO_VIRTFB |
  47                 FBINFO_HWACCEL_IMAGEBLIT | FBINFO_HWACCEL_FILLRECT |
  48                 FBINFO_HWACCEL_COPYAREA | FBINFO_MISC_ALWAYS_SETPAR;
  49
  50 /*
  51  * There are many DisplayLink-based graphics products, all with unique PIDs.
  52  * So we match on DisplayLink's VID + Vendor-Defined Interface Class (0xff)
  53  * We also require a match on SubClass (0x00) and Protocol (0x00),
  54  * which is compatible with all known USB 2.0 era graphics chips and firmware,
  55  * but allows DisplayLink to increment those for any future incompatible chips
  56  */
  57 static struct usb_device_id id_table[] = {
  58         {.idVendor = 0x17e9,
  59          .bInterfaceClass = 0xff,
  60          .bInterfaceSubClass = 0x00,
  61          .bInterfaceProtocol = 0x00,
  62          .match_flags = USB_DEVICE_ID_MATCH_VENDOR |
  63                 USB_DEVICE_ID_MATCH_INT_CLASS |
  64                 USB_DEVICE_ID_MATCH_INT_SUBCLASS |
  65                 USB_DEVICE_ID_MATCH_INT_PROTOCOL,
  66         },
  67         {},
  68 };
  69 MODULE_DEVICE_TABLE(usb, id_table);
  70
  71 /* module options */
  72 static int console = 1; /* Allow fbcon to open framebuffer */
  73 static int fb_defio = 1;  /* Detect mmap writes using page faults */
  74 static int shadow = 1; /* Optionally disable shadow framebuffer */
  75
  76 /* dlfb keeps a list of urbs for efficient bulk transfers */
  77 static void dlfb_urb_completion(struct urb *urb);
  78 static struct urb *dlfb_get_urb(struct dlfb_data *dev);
  79 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb * urb, size_t len);
  80 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size);
  81 static void dlfb_free_urb_list(struct dlfb_data *dev);
  82
  83 /*
  84  * All DisplayLink bulk operations start with 0xAF, followed by specific code
  85  * All operations are written to buffers which then later get sent to device
  86  */
  87 static char *dlfb_set_register(char *buf, u8 reg, u8 val)
  88 {
  89         *buf++ = 0xAF;
  90         *buf++ = 0x20;
  91         *buf++ = reg;
  92         *buf++ = val;
  93         return buf;
  94 }
  95
  96 static char *dlfb_vidreg_lock(char *buf)
  97 {
  98         return dlfb_set_register(buf, 0xFF, 0x00);
  99 }
 100
 101 static char *dlfb_vidreg_unlock(char *buf)
 102 {
 103         return dlfb_set_register(buf, 0xFF, 0xFF);
 104 }
 105
 106 /*
 107  * Map FB_BLANK_* to DisplayLink register
 108  * DLReg FB_BLANK_*
 109  * ----- -----------------------------
 110  *  0x00 FB_BLANK_UNBLANK (0)
 111  *  0x01 FB_BLANK (1)
 112  *  0x03 FB_BLANK_VSYNC_SUSPEND (2)
 113  *  0x05 FB_BLANK_HSYNC_SUSPEND (3)
 114  *  0x07 FB_BLANK_POWERDOWN (4) Note: requires modeset to come back
 115  */
 116 static char *dlfb_blanking(char *buf, int fb_blank)
 117 {
 118         u8 reg;
 119
 120         switch (fb_blank) {
 121         case FB_BLANK_POWERDOWN:
 122                 reg = 0x07;
 123                 break;
 124         case FB_BLANK_HSYNC_SUSPEND:
 125                 reg = 0x05;
 126                 break;
 127         case FB_BLANK_VSYNC_SUSPEND:
 128                 reg = 0x03;
 129                 break;
 130         case FB_BLANK_NORMAL:
 131                 reg = 0x01;
 132                 break;
 133         default:
 134                 reg = 0x00;
 135         }
 136
 137         buf = dlfb_set_register(buf, 0x1F, reg);
 138
 139         return buf;
 140 }
 141
 142 static char *dlfb_set_color_depth(char *buf, u8 selection)
 143 {
 144         return dlfb_set_register(buf, 0x00, selection);
 145 }
 146
 147 static char *dlfb_set_base16bpp(char *wrptr, u32 base)
 148 {
 149         /* the base pointer is 16 bits wide, 0x20 is hi byte. */
 150         wrptr = dlfb_set_register(wrptr, 0x20, base >> 16);
 151         wrptr = dlfb_set_register(wrptr, 0x21, base >> 8);
 152         return dlfb_set_register(wrptr, 0x22, base);
 153 }
 154
 155 /*
 156  * DisplayLink HW has separate 16bpp and 8bpp framebuffers.
 157  * In 24bpp modes, the low 323 RGB bits go in the 8bpp framebuffer
 158  */
 159 static char *dlfb_set_base8bpp(char *wrptr, u32 base)
 160 {
 161         wrptr = dlfb_set_register(wrptr, 0x26, base >> 16);
 162         wrptr = dlfb_set_register(wrptr, 0x27, base >> 8);
 163         return dlfb_set_register(wrptr, 0x28, base);
 164 }
 165
 166 static char *dlfb_set_register_16(char *wrptr, u8 reg, u16 value)
 167 {
 168         wrptr = dlfb_set_register(wrptr, reg, value >> 8);
 169         return dlfb_set_register(wrptr, reg+1, value);
 170 }
 171
 172 /*
 173  * This is kind of weird because the controller takes some
 174  * register values in a different byte order than other registers.
 175  */
 176 static char *dlfb_set_register_16be(char *wrptr, u8 reg, u16 value)
 177 {
 178         wrptr = dlfb_set_register(wrptr, reg, value);
 179         return dlfb_set_register(wrptr, reg+1, value >> 8);
 180 }
 181
 182 /*
 183  * LFSR is linear feedback shift register. The reason we have this is
 184  * because the display controller needs to minimize the clock depth of
 185  * various counters used in the display path. So this code reverses the
 186  * provided value into the lfsr16 value by counting backwards to get
 187  * the value that needs to be set in the hardware comparator to get the
 188  * same actual count. This makes sense once you read above a couple of
 189  * times and think about it from a hardware perspective.
 190  */
 191 static u16 dlfb_lfsr16(u16 actual_count)
 192 {
 193         u32 lv = 0xFFFF; /* This is the lfsr value that the hw starts with */
 194
 195         while (actual_count--) {
 196                 lv =     ((lv << 1) |
 197                         (((lv >> 15) ^ (lv >> 4) ^ (lv >> 2) ^ (lv >> 1)) & 1))
 198                         & 0xFFFF;
 199         }
 200
 201         return (u16) lv;
 202 }
 203
 204 /*
 205  * This does LFSR conversion on the value that is to be written.
 206  * See LFSR explanation above for more detail.
 207  */
 208 static char *dlfb_set_register_lfsr16(char *wrptr, u8 reg, u16 value)
 209 {
 210         return dlfb_set_register_16(wrptr, reg, dlfb_lfsr16(value));
 211 }
 212
 213 /*
 214  * This takes a standard fbdev screeninfo struct and all of its monitor mode
 215  * details and converts them into the DisplayLink equivalent register commands.
 216  */
 217 static char *dlfb_set_vid_cmds(char *wrptr, struct fb_var_screeninfo *var)
 218 {
 219         u16 xds, yds;
 220         u16 xde, yde;
 221         u16 yec;
 222
 223         /* x display start */
 224         xds = var->left_margin + var->hsync_len;
 225         wrptr = dlfb_set_register_lfsr16(wrptr, 0x01, xds);
 226         /* x display end */
 227         xde = xds + var->xres;
 228         wrptr = dlfb_set_register_lfsr16(wrptr, 0x03, xde);
 229
 230         /* y display start */
 231         yds = var->upper_margin + var->vsync_len;
 232         wrptr = dlfb_set_register_lfsr16(wrptr, 0x05, yds);
 233         /* y display end */
 234         yde = yds + var->yres;
 235         wrptr = dlfb_set_register_lfsr16(wrptr, 0x07, yde);
 236
 237         /* x end count is active + blanking - 1 */
 238         wrptr = dlfb_set_register_lfsr16(wrptr, 0x09,
 239                         xde + var->right_margin - 1);
 240
 241         /* libdlo hardcodes hsync start to 1 */
 242         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0B, 1);
 243
 244         /* hsync end is width of sync pulse + 1 */
 245         wrptr = dlfb_set_register_lfsr16(wrptr, 0x0D, var->hsync_len + 1);
 246
 247         /* hpixels is active pixels */
 248         wrptr = dlfb_set_register_16(wrptr, 0x0F, var->xres);
 249
 250         /* yendcount is vertical active + vertical blanking */
 251         yec = var->yres + var->upper_margin + var->lower_margin +
 252                         var->vsync_len;
 253         wrptr = dlfb_set_register_lfsr16(wrptr, 0x11, yec);
 254
 255         /* libdlo hardcodes vsync start to 0 */
 256         wrptr = dlfb_set_register_lfsr16(wrptr, 0x13, 0);
 257
 258         /* vsync end is width of vsync pulse */
 259         wrptr = dlfb_set_register_lfsr16(wrptr, 0x15, var->vsync_len);
 260
 261         /* vpixels is active pixels */
 262         wrptr = dlfb_set_register_16(wrptr, 0x17, var->yres);
 263
 264         /* convert picoseconds to 5kHz multiple for pclk5k = x * 1E12/5k */
 265         wrptr = dlfb_set_register_16be(wrptr, 0x1B,
 266                         200*1000*1000/var->pixclock);
 267
 268         return wrptr;
 269 }
 270
 271 /*
 272  * This takes a standard fbdev screeninfo struct that was fetched or prepared
 273  * and then generates the appropriate command sequence that then drives the
 274  * display controller.
 275  */
 276 static int dlfb_set_video_mode(struct dlfb_data *dev,
 277                                 struct fb_var_screeninfo *var)
 278 {
 279         char *buf;
 280         char *wrptr;
 281         int retval = 0;
 282         int writesize;
 283         struct urb *urb;
 284
 285         if (!atomic_read(&dev->usb_active))
 286                 return -EPERM;
 287
 288         urb = dlfb_get_urb(dev);
 289         if (!urb)
 290                 return -ENOMEM;
 291
 292         buf = (char *) urb->transfer_buffer;
 293
 294         /*
 295         * This first section has to do with setting the base address on the
 296         * controller * associated with the display. There are 2 base
 297         * pointers, currently, we only * use the 16 bpp segment.
 298         */
 299         wrptr = dlfb_vidreg_lock(buf);
 300         wrptr = dlfb_set_color_depth(wrptr, 0x00);
 301         /* set base for 16bpp segment to 0 */
 302         wrptr = dlfb_set_base16bpp(wrptr, 0);
 303         /* set base for 8bpp segment to end of fb */
 304         wrptr = dlfb_set_base8bpp(wrptr, dev->info->fix.smem_len);
 305
 306         wrptr = dlfb_set_vid_cmds(wrptr, var);
 307         wrptr = dlfb_blanking(wrptr, FB_BLANK_UNBLANK);
 308         wrptr = dlfb_vidreg_unlock(wrptr);
 309
 310         writesize = wrptr - buf;
 311
 312         retval = dlfb_submit_urb(dev, urb, writesize);
 313
 314         dev->blank_mode = FB_BLANK_UNBLANK;
 315
 316         return retval;
 317 }
 318
 319 static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma)
 320 {
 321         unsigned long start = vma->vm_start;
 322         unsigned long size = vma->vm_end - vma->vm_start;
 323         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 324         unsigned long page, pos;
 325
 326         if (offset + size > info->fix.smem_len)
 327                 return -EINVAL;
 328
 329         pos = (unsigned long)info->fix.smem_start + offset;
 330
 331         pr_notice("mmap() framebuffer addr:%lu size:%lu\n",
 332                   pos, size);
 333
 334         while (size > 0) {
 335                 page = vmalloc_to_pfn((void *)pos);
 336                 if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
 337                         return -EAGAIN;
 338
 339                 start += PAGE_SIZE;
 340                 pos += PAGE_SIZE;
 341                 if (size > PAGE_SIZE)
 342                         size -= PAGE_SIZE;
 343                 else
 344                         size = 0;
 345         }
 346
 347         vma->vm_flags |= VM_RESERVED;   /* avoid to swap out this VMA */
 348         return 0;
 349 }
 350
 351 /*
 352  * Trims identical data from front and back of line
 353  * Sets new front buffer address and width
 354  * And returns byte count of identical pixels
 355  * Assumes CPU natural alignment (unsigned long)
 356  * for back and front buffer ptrs and width
 357  */
 358 static int dlfb_trim_hline(const u8 *bback, const u8 **bfront, int *width_bytes)
 359 {
 360         int j, k;
 361         const unsigned long *back = (const unsigned long *) bback;
 362         const unsigned long *front = (const unsigned long *) *bfront;
 363         const int width = *width_bytes / sizeof(unsigned long);
 364         int identical = width;
 365         int start = width;
 366         int end = width;
 367
 368         prefetch((void *) front);
 369         prefetch((void *) back);
 370
 371         for (j = 0; j < width; j++) {
 372                 if (back[j] != front[j]) {
 373                         start = j;
 374                         break;
 375                 }
 376         }
 377
 378         for (k = width - 1; k > j; k--) {
 379                 if (back[k] != front[k]) {
 380                         end = k+1;
 381                         break;
 382                 }
 383         }
 384
 385         identical = start + (width - end);
 386         *bfront = (u8 *) &front[start];
 387         *width_bytes = (end - start) * sizeof(unsigned long);
 388
 389         return identical * sizeof(unsigned long);
 390 }
 391
 392 /*
 393  * Render a command stream for an encoded horizontal line segment of pixels.
 394  *
 395  * A command buffer holds several commands.
 396  * It always begins with a fresh command header
 397  * (the protocol doesn't require this, but we enforce it to allow
 398  * multiple buffers to be potentially encoded and sent in parallel).
 399  * A single command encodes one contiguous horizontal line of pixels
 400  *
 401  * The function relies on the client to do all allocation, so that
 402  * rendering can be done directly to output buffers (e.g. USB URBs).
 403  * The function fills the supplied command buffer, providing information
 404  * on where it left off, so the client may call in again with additional
 405  * buffers if the line will take several buffers to complete.
 406  *
 407  * A single command can transmit a maximum of 256 pixels,
 408  * regardless of the compression ratio (protocol design limit).
 409  * To the hardware, 0 for a size byte means 256
 410  *
 411  * Rather than 256 pixel commands which are either rl or raw encoded,
 412  * the rlx command simply assumes alternating raw and rl spans within one cmd.
 413  * This has a slightly larger header overhead, but produces more even results.
 414  * It also processes all data (read and write) in a single pass.
 415  * Performance benchmarks of common cases show it having just slightly better
 416  * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
 417  * But for very rl friendly data, will compress not quite as well.
 418  */
 419 static void dlfb_compress_hline(
 420         const uint16_t **pixel_start_ptr,
 421         const uint16_t *const pixel_end,
 422         uint32_t *device_address_ptr,
 423         uint8_t **command_buffer_ptr,
 424         const uint8_t *const cmd_buffer_end)
 425 {
 426         const uint16_t *pixel = *pixel_start_ptr;
 427         uint32_t dev_addr  = *device_address_ptr;
 428         uint8_t *cmd = *command_buffer_ptr;
 429         const int bpp = 2;
 430
 431         while ((pixel_end > pixel) &&
 432                (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
 433                 uint8_t *raw_pixels_count_byte = 0;
 434                 uint8_t *cmd_pixels_count_byte = 0;
 435                 const uint16_t *raw_pixel_start = 0;
 436                 const uint16_t *cmd_pixel_start, *cmd_pixel_end = 0;
 437
 438                 prefetchw((void *) cmd); /* pull in one cache line at least */
 439
 440                 *cmd++ = 0xAF;
 441                 *cmd++ = 0x6B;
 442                 *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
 443                 *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
 444                 *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
 445
 446                 cmd_pixels_count_byte = cmd++; /*  we'll know this later */
 447                 cmd_pixel_start = pixel;
 448
 449                 raw_pixels_count_byte = cmd++; /*  we'll know this later */
 450                 raw_pixel_start = pixel;
 451
 452                 cmd_pixel_end = pixel + min(MAX_CMD_PIXELS + 1,
 453                         min((int)(pixel_end - pixel),
 454                             (int)(cmd_buffer_end - cmd) / bpp));
 455
 456                 prefetch_range((void *) pixel, (cmd_pixel_end - pixel) * bpp);
 457
 458                 while (pixel < cmd_pixel_end) {
 459                         const uint16_t * const repeating_pixel = pixel;
 460
 461                         *(uint16_t *)cmd = cpu_to_be16p(pixel);
 462                         cmd += 2;
 463                         pixel++;
 464
 465                         if (unlikely((pixel < cmd_pixel_end) &&
 466                                      (*pixel == *repeating_pixel))) {
 467                                 /* go back and fill in raw pixel count */
 468                                 *raw_pixels_count_byte = ((repeating_pixel -
 469                                                 raw_pixel_start) + 1) & 0xFF;
 470
 471                                 while ((pixel < cmd_pixel_end)
 472                                        && (*pixel == *repeating_pixel)) {
 473                                         pixel++;
 474                                 }
 475
 476                                 /* immediately after raw data is repeat byte */
 477                                 *cmd++ = ((pixel - repeating_pixel) - 1) & 0xFF;
 478
 479                                 /* Then start another raw pixel span */
 480                                 raw_pixel_start = pixel;
 481                                 raw_pixels_count_byte = cmd++;
 482                         }
 483                 }
 484
 485                 if (pixel > raw_pixel_start) {
 486                         /* finalize last RAW span */
 487                         *raw_pixels_count_byte = (pixel-raw_pixel_start) & 0xFF;
 488                 }
 489
 490                 *cmd_pixels_count_byte = (pixel - cmd_pixel_start) & 0xFF;
 491                 dev_addr += (pixel - cmd_pixel_start) * bpp;
 492         }
 493
 494         if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
 495                 /* Fill leftover bytes with no-ops */
 496                 if (cmd_buffer_end > cmd)
 497                         memset(cmd, 0xAF, cmd_buffer_end - cmd);
 498                 cmd = (uint8_t *) cmd_buffer_end;
 499         }
 500
 501         *command_buffer_ptr = cmd;
 502         *pixel_start_ptr = pixel;
 503         *device_address_ptr = dev_addr;
 504
 505         return;
 506 }
 507
 508 /*
 509  * There are 3 copies of every pixel: The front buffer that the fbdev
 510  * client renders to, the actual framebuffer across the USB bus in hardware
 511  * (that we can only write to, slowly, and can never read), and (optionally)
 512  * our shadow copy that tracks what's been sent to that hardware buffer.
 513  */
 514 static int dlfb_render_hline(struct dlfb_data *dev, struct urb **urb_ptr,
 515                               const char *front, char **urb_buf_ptr,
 516                               u32 byte_offset, u32 byte_width,
 517                               int *ident_ptr, int *sent_ptr)
 518 {
 519         const u8 *line_start, *line_end, *next_pixel;
 520         u32 dev_addr = dev->base16 + byte_offset;
 521         struct urb *urb = *urb_ptr;
 522         u8 *cmd = *urb_buf_ptr;
 523         u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
 524
 525         line_start = (u8 *) (front + byte_offset);
 526         next_pixel = line_start;
 527         line_end = next_pixel + byte_width;
 528
 529         if (dev->backing_buffer) {
 530                 int offset;
 531                 const u8 *back_start = (u8 *) (dev->backing_buffer
 532                                                 + byte_offset);
 533
 534                 *ident_ptr += dlfb_trim_hline(back_start, &next_pixel,
 535                         &byte_width);
 536
 537                 offset = next_pixel - line_start;
 538                 line_end = next_pixel + byte_width;
 539                 dev_addr += offset;
 540                 back_start += offset;
 541                 line_start += offset;
 542
 543                 memcpy((char *)back_start, (char *) line_start,
 544                        byte_width);
 545         }
 546
 547         while (next_pixel < line_end) {
 548
 549                 dlfb_compress_hline((const uint16_t **) &next_pixel,
 550                              (const uint16_t *) line_end, &dev_addr,
 551                         (u8 **) &cmd, (u8 *) cmd_end);
 552
 553                 if (cmd >= cmd_end) {
 554                         int len = cmd - (u8 *) urb->transfer_buffer;
 555                         if (dlfb_submit_urb(dev, urb, len))
 556                                 return 1; /* lost pixels is set */
 557                         *sent_ptr += len;
 558                         urb = dlfb_get_urb(dev);
 559                         if (!urb)
 560                                 return 1; /* lost_pixels is set */
 561                         *urb_ptr = urb;
 562                         cmd = urb->transfer_buffer;
 563                         cmd_end = &cmd[urb->transfer_buffer_length];
 564                 }
 565         }
 566
 567         *urb_buf_ptr = cmd;
 568
 569         return 0;
 570 }
 571
 572 int dlfb_handle_damage(struct dlfb_data *dev, int x, int y,
 573                int width, int height, char *data)
 574 {
 575         int i, ret;
 576         char *cmd;
 577         cycles_t start_cycles, end_cycles;
 578         int bytes_sent = 0;
 579         int bytes_identical = 0;
 580         struct urb *urb;
 581         int aligned_x;
 582
 583         start_cycles = get_cycles();
 584
 585         aligned_x = DL_ALIGN_DOWN(x, sizeof(unsigned long));
 586         width = DL_ALIGN_UP(width + (x-aligned_x), sizeof(unsigned long));
 587         x = aligned_x;
 588
 589         if ((width <= 0) ||
 590             (x + width > dev->info->var.xres) ||
 591             (y + height > dev->info->var.yres))
 592                 return -EINVAL;
 593
 594         if (!atomic_read(&dev->usb_active))
 595                 return 0;
 596
 597         urb = dlfb_get_urb(dev);
 598         if (!urb)
 599                 return 0;
 600         cmd = urb->transfer_buffer;
 601
 602         for (i = y; i < y + height ; i++) {
 603                 const int line_offset = dev->info->fix.line_length * i;
 604                 const int byte_offset = line_offset + (x * BPP);
 605
 606                 if (dlfb_render_hline(dev, &urb,
 607                                       (char *) dev->info->fix.smem_start,
 608                                       &cmd, byte_offset, width * BPP,
 609                                       &bytes_identical, &bytes_sent))
 610                         goto error;
 611         }
 612
 613         if (cmd > (char *) urb->transfer_buffer) {
 614                 /* Send partial buffer remaining before exiting */
 615                 int len = cmd - (char *) urb->transfer_buffer;
 616                 ret = dlfb_submit_urb(dev, urb, len);
 617                 bytes_sent += len;
 618         } else
 619                 dlfb_urb_completion(urb);
 620
 621 error:
 622         atomic_add(bytes_sent, &dev->bytes_sent);
 623         atomic_add(bytes_identical, &dev->bytes_identical);
 624         atomic_add(width*height*2, &dev->bytes_rendered);
 625         end_cycles = get_cycles();
 626         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 627                     >> 10)), /* Kcycles */
 628                    &dev->cpu_kcycles_used);
 629
 630         return 0;
 631 }
 632
 633 /*
 634  * Path triggered by usermode clients who write to filesystem
 635  * e.g. cat filename > /dev/fb1
 636  * Not used by X Windows or text-mode console. But useful for testing.
 637  * Slow because of extra copy and we must assume all pixels dirty.
 638  */
 639 static ssize_t dlfb_ops_write(struct fb_info *info, const char __user *buf,
 640                           size_t count, loff_t *ppos)
 641 {
 642         ssize_t result;
 643         struct dlfb_data *dev = info->par;
 644         u32 offset = (u32) *ppos;
 645
 646         result = fb_sys_write(info, buf, count, ppos);
 647
 648         if (result > 0) {
 649                 int start = max((int)(offset / info->fix.line_length) - 1, 0);
 650                 int lines = min((u32)((result / info->fix.line_length) + 1),
 651                                 (u32)info->var.yres);
 652
 653                 dlfb_handle_damage(dev, 0, start, info->var.xres,
 654                         lines, info->screen_base);
 655         }
 656
 657         return result;
 658 }
 659
 660 /* hardware has native COPY command (see libdlo), but not worth it for fbcon */
 661 static void dlfb_ops_copyarea(struct fb_info *info,
 662                                 const struct fb_copyarea *area)
 663 {
 664
 665         struct dlfb_data *dev = info->par;
 666
 667         sys_copyarea(info, area);
 668
 669         dlfb_handle_damage(dev, area->dx, area->dy,
 670                         area->width, area->height, info->screen_base);
 671 }
 672
 673 static void dlfb_ops_imageblit(struct fb_info *info,
 674                                 const struct fb_image *image)
 675 {
 676         struct dlfb_data *dev = info->par;
 677
 678         sys_imageblit(info, image);
 679
 680         dlfb_handle_damage(dev, image->dx, image->dy,
 681                         image->width, image->height, info->screen_base);
 682 }
 683
 684 static void dlfb_ops_fillrect(struct fb_info *info,
 685                           const struct fb_fillrect *rect)
 686 {
 687         struct dlfb_data *dev = info->par;
 688
 689         sys_fillrect(info, rect);
 690
 691         dlfb_handle_damage(dev, rect->dx, rect->dy, rect->width,
 692                               rect->height, info->screen_base);
 693 }
 694
 695 /*
 696  * NOTE: fb_defio.c is holding info->fbdefio.mutex
 697  *   Touching ANY framebuffer memory that triggers a page fault
 698  *   in fb_defio will cause a deadlock, when it also tries to
 699  *   grab the same mutex.
 700  */
 701 static void dlfb_dpy_deferred_io(struct fb_info *info,
 702                                 struct list_head *pagelist)
 703 {
 704         struct page *cur;
 705         struct fb_deferred_io *fbdefio = info->fbdefio;
 706         struct dlfb_data *dev = info->par;
 707         struct urb *urb;
 708         char *cmd;
 709         cycles_t start_cycles, end_cycles;
 710         int bytes_sent = 0;
 711         int bytes_identical = 0;
 712         int bytes_rendered = 0;
 713
 714         if (!fb_defio)
 715                 return;
 716
 717         if (!atomic_read(&dev->usb_active))
 718                 return;
 719
 720         start_cycles = get_cycles();
 721
 722         urb = dlfb_get_urb(dev);
 723         if (!urb)
 724                 return;
 725
 726         cmd = urb->transfer_buffer;
 727
 728         /* walk the written page list and render each to device */
 729         list_for_each_entry(cur, &fbdefio->pagelist, lru) {
 730
 731                 if (dlfb_render_hline(dev, &urb, (char *) info->fix.smem_start,
 732                                   &cmd, cur->index << PAGE_SHIFT,
 733                                   PAGE_SIZE, &bytes_identical, &bytes_sent))
 734                         goto error;
 735                 bytes_rendered += PAGE_SIZE;
 736         }
 737
 738         if (cmd > (char *) urb->transfer_buffer) {
 739                 /* Send partial buffer remaining before exiting */
 740                 int len = cmd - (char *) urb->transfer_buffer;
 741                 dlfb_submit_urb(dev, urb, len);
 742                 bytes_sent += len;
 743         } else
 744                 dlfb_urb_completion(urb);
 745
 746 error:
 747         atomic_add(bytes_sent, &dev->bytes_sent);
 748         atomic_add(bytes_identical, &dev->bytes_identical);
 749         atomic_add(bytes_rendered, &dev->bytes_rendered);
 750         end_cycles = get_cycles();
 751         atomic_add(((unsigned int) ((end_cycles - start_cycles)
 752                     >> 10)), /* Kcycles */
 753                    &dev->cpu_kcycles_used);
 754 }
 755
 756 static int dlfb_get_edid(struct dlfb_data *dev, char *edid, int len)
 757 {
 758         int i;
 759         int ret;
 760         char *rbuf;
 761
 762         rbuf = kmalloc(2, GFP_KERNEL);
 763         if (!rbuf)
 764                 return 0;
 765
 766         for (i = 0; i < len; i++) {
 767                 ret = usb_control_msg(dev->udev,
 768                                     usb_rcvctrlpipe(dev->udev, 0), (0x02),
 769                                     (0x80 | (0x02 << 5)), i << 8, 0xA1, rbuf, 2,
 770                                     HZ);
 771                 if (ret < 1) {
 772                         pr_err("Read EDID byte %d failed err %x\n", i, ret);
 773                         i--;
 774                         break;
 775                 }
 776                 edid[i] = rbuf[1];
 777         }
 778
 779         kfree(rbuf);
 780
 781         return i;
 782 }
 783
 784 static int dlfb_ops_ioctl(struct fb_info *info, unsigned int cmd,
 785                                 unsigned long arg)
 786 {
 787
 788         struct dlfb_data *dev = info->par;
 789
 790         if (!atomic_read(&dev->usb_active))
 791                 return 0;
 792
 793         /* TODO: Update X server to get this from sysfs instead */
 794         if (cmd == DLFB_IOCTL_RETURN_EDID) {
 795                 void __user *edid = (void __user *)arg;
 796                 if (copy_to_user(edid, dev->edid, dev->edid_size))
 797                         return -EFAULT;
 798                 return 0;
 799         }
 800
 801         /* TODO: Help propose a standard fb.h ioctl to report mmap damage */
 802         if (cmd == DLFB_IOCTL_REPORT_DAMAGE) {
 803                 struct dloarea area;
 804
 805                 if (copy_from_user(&area, (void __user *)arg,
 806                                   sizeof(struct dloarea)))
 807                         return -EFAULT;
 808
 809                 /*
 810                  * If we have a damage-aware client, turn fb_defio "off"
 811                  * To avoid perf imact of unnecessary page fault handling.
 812                  * Done by resetting the delay for this fb_info to a very
 813                  * long period. Pages will become writable and stay that way.
 814                  * Reset to normal value when all clients have closed this fb.
 815                  */
 816                 if (info->fbdefio)
 817                         info->fbdefio->delay = DL_DEFIO_WRITE_DISABLE;
 818
 819                 if (area.x < 0)
 820                         area.x = 0;
 821
 822                 if (area.x > info->var.xres)
 823                         area.x = info->var.xres;
 824
 825                 if (area.y < 0)
 826                         area.y = 0;
 827
 828                 if (area.y > info->var.yres)
 829                         area.y = info->var.yres;
 830
 831                 dlfb_handle_damage(dev, area.x, area.y, area.w, area.h,
 832                            info->screen_base);
 833         }
 834
 835         return 0;
 836 }
 837
 838 /* taken from vesafb */
 839 static int
 840 dlfb_ops_setcolreg(unsigned regno, unsigned red, unsigned green,
 841                unsigned blue, unsigned transp, struct fb_info *info)
 842 {
 843         int err = 0;
 844
 845         if (regno >= info->cmap.len)
 846                 return 1;
 847
 848         if (regno < 16) {
 849                 if (info->var.red.offset == 10) {
 850                         /* 1:5:5:5 */
 851                         ((u32 *) (info->pseudo_palette))[regno] =
 852                             ((red & 0xf800) >> 1) |
 853                             ((green & 0xf800) >> 6) | ((blue & 0xf800) >> 11);
 854                 } else {
 855                         /* 0:5:6:5 */
 856                         ((u32 *) (info->pseudo_palette))[regno] =
 857                             ((red & 0xf800)) |
 858                             ((green & 0xfc00) >> 5) | ((blue & 0xf800) >> 11);
 859                 }
 860         }
 861
 862         return err;
 863 }
 864
 865 /*
 866  * It's common for several clients to have framebuffer open simultaneously.
 867  * e.g. both fbcon and X. Makes things interesting.
 868  * Assumes caller is holding info->lock (for open and release at least)
 869  */
 870 static int dlfb_ops_open(struct fb_info *info, int user)
 871 {
 872         struct dlfb_data *dev = info->par;
 873
 874         /*
 875          * fbcon aggressively connects to first framebuffer it finds,
 876          * preventing other clients (X) from working properly. Usually
 877          * not what the user wants. Fail by default with option to enable.
 878          */
 879         if ((user == 0) && (!console))
 880                 return -EBUSY;
 881
 882         /* If the USB device is gone, we don't accept new opens */
 883         if (dev->virtualized)
 884                 return -ENODEV;
 885
 886         dev->fb_count++;
 887
 888         kref_get(&dev->kref);
 889
 890         if (fb_defio && (info->fbdefio == NULL)) {
 891                 /* enable defio at last moment if not disabled by client */
 892
 893                 struct fb_deferred_io *fbdefio;
 894
 895                 fbdefio = kmalloc(sizeof(struct fb_deferred_io), GFP_KERNEL);
 896
 897                 if (fbdefio) {
 898                         fbdefio->delay = DL_DEFIO_WRITE_DELAY;
 899                         fbdefio->deferred_io = dlfb_dpy_deferred_io;
 900                 }
 901
 902                 info->fbdefio = fbdefio;
 903                 fb_deferred_io_init(info);
 904         }
 905
 906         pr_notice("open /dev/fb%d user=%d fb_info=%p count=%d\n",
 907             info->node, user, info, dev->fb_count);
 908
 909         return 0;
 910 }
 911
 912 /*
 913  * Called when all client interfaces to start transactions have been disabled,
 914  * and all references to our device instance (dlfb_data) are released.
 915  * Every transaction must have a reference, so we know are fully spun down
 916  */
 917 static void dlfb_free(struct kref *kref)
 918 {
 919         struct dlfb_data *dev = container_of(kref, struct dlfb_data, kref);
 920
 921         /* this function will wait for all in-flight urbs to complete */
 922         if (dev->urbs.count > 0)
 923                 dlfb_free_urb_list(dev);
 924
 925         if (dev->backing_buffer)
 926                 vfree(dev->backing_buffer);
 927
 928         kfree(dev->edid);
 929
 930         pr_warn("freeing dlfb_data %p\n", dev);
 931
 932         kfree(dev);
 933 }
 934
 935 static void dlfb_release_urb_work(struct work_struct *work)
 936 {
 937         struct urb_node *unode = container_of(work, struct urb_node,
 938                                               release_urb_work.work);
 939
 940         up(&unode->dev->urbs.limit_sem);
 941 }
 942
 943 static void dlfb_free_framebuffer_work(struct work_struct *work)
 944 {
 945         struct dlfb_data *dev = container_of(work, struct dlfb_data,
 946                                              free_framebuffer_work.work);
 947         struct fb_info *info = dev->info;
 948         int node = info->node;
 949
 950         unregister_framebuffer(info);
 951
 952         if (info->cmap.len != 0)
 953                 fb_dealloc_cmap(&info->cmap);
 954         if (info->monspecs.modedb)
 955                 fb_destroy_modedb(info->monspecs.modedb);
 956         if (info->screen_base)
 957                 vfree(info->screen_base);
 958
 959         fb_destroy_modelist(&info->modelist);
 960
 961         dev->info = 0;
 962
 963         /* Assume info structure is freed after this point */
 964         framebuffer_release(info);
 965
 966         pr_warn("fb_info for /dev/fb%d has been freed\n", node);
 967
 968         /* ref taken in probe() as part of registering framebfufer */
 969         kref_put(&dev->kref, dlfb_free);
 970 }
 971
 972 /*
 973  * Assumes caller is holding info->lock mutex (for open and release at least)
 974  */
 975 static int dlfb_ops_release(struct fb_info *info, int user)
 976 {
 977         struct dlfb_data *dev = info->par;
 978
 979         dev->fb_count--;
 980
 981         /* We can't free fb_info here - fbmem will touch it when we return */
 982         if (dev->virtualized && (dev->fb_count == 0))
 983                 schedule_delayed_work(&dev->free_framebuffer_work, HZ);
 984
 985         if ((dev->fb_count == 0) && (info->fbdefio)) {
 986                 fb_deferred_io_cleanup(info);
 987                 kfree(info->fbdefio);
 988                 info->fbdefio = NULL;
 989                 info->fbops->fb_mmap = dlfb_ops_mmap;
 990         }
 991
 992         pr_warn("released /dev/fb%d user=%d count=%d\n",
 993                   info->node, user, dev->fb_count);
 994
 995         kref_put(&dev->kref, dlfb_free);
 996
 997         return 0;
 998 }
 999
1000 /*
1001  * Check whether a video mode is supported by the DisplayLink chip
1002  * We start from monitor's modes, so don't need to filter that here
1003  */
1004 static int dlfb_is_valid_mode(struct fb_videomode *mode,
1005                 struct fb_info *info)
1006 {
1007         struct dlfb_data *dev = info->par;
1008
1009         if (mode->xres * mode->yres > dev->sku_pixel_limit) {
1010                 pr_warn("%dx%d beyond chip capabilities\n",
1011                        mode->xres, mode->yres);
1012                 return 0;
1013         }
1014
1015         pr_info("%dx%d valid mode\n", mode->xres, mode->yres);
1016
1017         return 1;
1018 }
1019
1020 static void dlfb_var_color_format(struct fb_var_screeninfo *var)
1021 {
1022         const struct fb_bitfield red = { 11, 5, 0 };
1023         const struct fb_bitfield green = { 5, 6, 0 };
1024         const struct fb_bitfield blue = { 0, 5, 0 };
1025
1026         var->bits_per_pixel = 16;
1027         var->red = red;
1028         var->green = green;
1029         var->blue = blue;
1030 }
1031
1032 static int dlfb_ops_check_var(struct fb_var_screeninfo *var,
1033                                 struct fb_info *info)
1034 {
1035         struct fb_videomode mode;
1036
1037         /* TODO: support dynamically changing framebuffer size */
1038         if ((var->xres * var->yres * 2) > info->fix.smem_len)
1039                 return -EINVAL;
1040
1041         /* set device-specific elements of var unrelated to mode */
1042         dlfb_var_color_format(var);
1043
1044         fb_var_to_videomode(&mode, var);
1045
1046         if (!dlfb_is_valid_mode(&mode, info))
1047                 return -EINVAL;
1048
1049         return 0;
1050 }
1051
1052 static int dlfb_ops_set_par(struct fb_info *info)
1053 {
1054         struct dlfb_data *dev = info->par;
1055         int result;
1056         u16 *pix_framebuffer;
1057         int i;
1058
1059         pr_notice("set_par mode %dx%d\n", info->var.xres, info->var.yres);
1060
1061         result = dlfb_set_video_mode(dev, &info->var);
1062
1063         if ((result == 0) && (dev->fb_count == 0)) {
1064
1065                 /* paint greenscreen */
1066
1067                 pix_framebuffer = (u16 *) info->screen_base;
1068                 for (i = 0; i < info->fix.smem_len / 2; i++)
1069                         pix_framebuffer[i] = 0x37e6;
1070
1071                 dlfb_handle_damage(dev, 0, 0, info->var.xres, info->var.yres,
1072                                    info->screen_base);
1073         }
1074
1075         return result;
1076 }
1077
1078 /* To fonzi the jukebox (e.g. make blanking changes take effect) */
1079 static char *dlfb_dummy_render(char *buf)
1080 {
1081         *buf++ = 0xAF;
1082         *buf++ = 0x6A; /* copy */
1083         *buf++ = 0x00; /* from address*/
1084         *buf++ = 0x00;
1085         *buf++ = 0x00;
1086         *buf++ = 0x01; /* one pixel */
1087         *buf++ = 0x00; /* to address */
1088         *buf++ = 0x00;
1089         *buf++ = 0x00;
1090         return buf;
1091 }
1092
1093 /*
1094  * In order to come back from full DPMS off, we need to set the mode again
1095  */
1096 static int dlfb_ops_blank(int blank_mode, struct fb_info *info)
1097 {
1098         struct dlfb_data *dev = info->par;
1099         char *bufptr;
1100         struct urb *urb;
1101
1102         pr_info("/dev/fb%d FB_BLANK mode %d --> %d\n",
1103                 info->node, dev->blank_mode, blank_mode);
1104
1105         if ((dev->blank_mode == FB_BLANK_POWERDOWN) &&
1106             (blank_mode != FB_BLANK_POWERDOWN)) {
1107
1108                 /* returning from powerdown requires a fresh modeset */
1109                 dlfb_set_video_mode(dev, &info->var);
1110         }
1111
1112         urb = dlfb_get_urb(dev);
1113         if (!urb)
1114                 return 0;
1115
1116         bufptr = (char *) urb->transfer_buffer;
1117         bufptr = dlfb_vidreg_lock(bufptr);
1118         bufptr = dlfb_blanking(bufptr, blank_mode);
1119         bufptr = dlfb_vidreg_unlock(bufptr);
1120
1121         /* seems like a render op is needed to have blank change take effect */
1122         bufptr = dlfb_dummy_render(bufptr);
1123
1124         dlfb_submit_urb(dev, urb, bufptr -
1125                         (char *) urb->transfer_buffer);
1126
1127         dev->blank_mode = blank_mode;
1128
1129         return 0;
1130 }
1131
1132 static struct fb_ops dlfb_ops = {
1133         .owner = THIS_MODULE,
1134         .fb_read = fb_sys_read,
1135         .fb_write = dlfb_ops_write,
1136         .fb_setcolreg = dlfb_ops_setcolreg,
1137         .fb_fillrect = dlfb_ops_fillrect,
1138         .fb_copyarea = dlfb_ops_copyarea,
1139         .fb_imageblit = dlfb_ops_imageblit,
1140         .fb_mmap = dlfb_ops_mmap,
1141         .fb_ioctl = dlfb_ops_ioctl,
1142         .fb_open = dlfb_ops_open,
1143         .fb_release = dlfb_ops_release,
1144         .fb_blank = dlfb_ops_blank,
1145         .fb_check_var = dlfb_ops_check_var,
1146         .fb_set_par = dlfb_ops_set_par,
1147 };
1148
1149
1150 /*
1151  * Assumes &info->lock held by caller
1152  * Assumes no active clients have framebuffer open
1153  */
1154 static int dlfb_realloc_framebuffer(struct dlfb_data *dev, struct fb_info *info)
1155 {
1156         int retval = -ENOMEM;
1157         int old_len = info->fix.smem_len;
1158         int new_len;
1159         unsigned char *old_fb = info->screen_base;
1160         unsigned char *new_fb;
1161         unsigned char *new_back = 0;
1162
1163         pr_warn("Reallocating framebuffer. Addresses will change!\n");
1164
1165         new_len = info->fix.line_length * info->var.yres;
1166
1167         if (PAGE_ALIGN(new_len) > old_len) {
1168                 /*
1169                  * Alloc system memory for virtual framebuffer
1170                  */
1171                 new_fb = vmalloc(new_len);
1172                 if (!new_fb) {
1173                         pr_err("Virtual framebuffer alloc failed\n");
1174                         goto error;
1175                 }
1176
1177                 if (info->screen_base) {
1178                         memcpy(new_fb, old_fb, old_len);
1179                         vfree(info->screen_base);
1180                 }
1181
1182                 info->screen_base = new_fb;
1183                 info->fix.smem_len = PAGE_ALIGN(new_len);
1184                 info->fix.smem_start = (unsigned long) new_fb;
1185                 info->flags = udlfb_info_flags;
1186
1187                 /*
1188                  * Second framebuffer copy to mirror the framebuffer state
1189                  * on the physical USB device. We can function without this.
1190                  * But with imperfect damage info we may send pixels over USB
1191                  * that were, in fact, unchanged - wasting limited USB bandwidth
1192                  */
1193                 if (shadow)
1194                         new_back = vzalloc(new_len);
1195                 if (!new_back)
1196                         pr_info("No shadow/backing buffer allocated\n");
1197                 else {
1198                         if (dev->backing_buffer)
1199                                 vfree(dev->backing_buffer);
1200                         dev->backing_buffer = new_back;
1201                 }
1202         }
1203
1204         retval = 0;
1205
1206 error:
1207         return retval;
1208 }
1209
1210 /*
1211  * 1) Get EDID from hw, or use sw default
1212  * 2) Parse into various fb_info structs
1213  * 3) Allocate virtual framebuffer memory to back highest res mode
1214  *
1215  * Parses EDID into three places used by various parts of fbdev:
1216  * fb_var_screeninfo contains the timing of the monitor's preferred mode
1217  * fb_info.monspecs is full parsed EDID info, including monspecs.modedb
1218  * fb_info.modelist is a linked list of all monitor & VESA modes which work
1219  *
1220  * If EDID is not readable/valid, then modelist is all VESA modes,
1221  * monspecs is NULL, and fb_var_screeninfo is set to safe VESA mode
1222  * Returns 0 if successful
1223  */
1224 static int dlfb_setup_modes(struct dlfb_data *dev,
1225                            struct fb_info *info,
1226                            char *default_edid, size_t default_edid_size)
1227 {
1228         int i;
1229         const struct fb_videomode *default_vmode = NULL;
1230         int result = 0;
1231         char *edid;
1232         int tries = 3;
1233
1234         if (info->dev) /* only use mutex if info has been registered */
1235                 mutex_lock(&info->lock);
1236
1237         edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
1238         if (!edid) {
1239                 result = -ENOMEM;
1240                 goto error;
1241         }
1242
1243         fb_destroy_modelist(&info->modelist);
1244         memset(&info->monspecs, 0, sizeof(info->monspecs));
1245
1246         /*
1247          * Try to (re)read EDID from hardware first
1248          * EDID data may return, but not parse as valid
1249          * Try again a few times, in case of e.g. analog cable noise
1250          */
1251         while (tries--) {
1252
1253                 i = dlfb_get_edid(dev, edid, EDID_LENGTH);
1254
1255                 if (i >= EDID_LENGTH)
1256                         fb_edid_to_monspecs(edid, &info->monspecs);
1257
1258                 if (info->monspecs.modedb_len > 0) {
1259                         dev->edid = edid;
1260                         dev->edid_size = i;
1261                         break;
1262                 }
1263         }
1264
1265         /* If that fails, use a previously returned EDID if available */
1266         if (info->monspecs.modedb_len == 0) {
1267
1268                 pr_err("Unable to get valid EDID from device/display\n");
1269
1270                 if (dev->edid) {
1271                         fb_edid_to_monspecs(dev->edid, &info->monspecs);
1272                         if (info->monspecs.modedb_len > 0)
1273                                 pr_err("Using previously queried EDID\n");
1274                 }
1275         }
1276
1277         /* If that fails, use the default EDID we were handed */
1278         if (info->monspecs.modedb_len == 0) {
1279                 if (default_edid_size >= EDID_LENGTH) {
1280                         fb_edid_to_monspecs(default_edid, &info->monspecs);
1281                         if (info->monspecs.modedb_len > 0) {
1282                                 memcpy(edid, default_edid, default_edid_size);
1283                                 dev->edid = edid;
1284                                 dev->edid_size = default_edid_size;
1285                                 pr_err("Using default/backup EDID\n");
1286                         }
1287                 }
1288         }
1289
1290         /* If we've got modes, let's pick a best default mode */
1291         if (info->monspecs.modedb_len > 0) {
1292
1293                 for (i = 0; i < info->monspecs.modedb_len; i++) {
1294                         if (dlfb_is_valid_mode(&info->monspecs.modedb[i], info))
1295                                 fb_add_videomode(&info->monspecs.modedb[i],
1296                                         &info->modelist);
1297                         else {
1298                                 if (i == 0)
1299                                         /* if we've removed top/best mode */
1300                                         info->monspecs.misc
1301                                                 &= ~FB_MISC_1ST_DETAIL;
1302                         }
1303                 }
1304
1305                 default_vmode = fb_find_best_display(&info->monspecs,
1306                                                      &info->modelist);
1307         }
1308
1309         /* If everything else has failed, fall back to safe default mode */
1310         if (default_vmode == NULL) {
1311
1312                 struct fb_videomode fb_vmode = {0};
1313
1314                 /*
1315                  * Add the standard VESA modes to our modelist
1316                  * Since we don't have EDID, there may be modes that
1317                  * overspec monitor and/or are incorrect aspect ratio, etc.
1318                  * But at least the user has a chance to choose
1319                  */
1320                 for (i = 0; i < VESA_MODEDB_SIZE; i++) {
1321                         if (dlfb_is_valid_mode((struct fb_videomode *)
1322                                                 &vesa_modes[i], info))
1323                                 fb_add_videomode(&vesa_modes[i],
1324                                                  &info->modelist);
1325                 }
1326
1327                 /*
1328                  * default to resolution safe for projectors
1329                  * (since they are most common case without EDID)
1330                  */
1331                 fb_vmode.xres = 800;
1332                 fb_vmode.yres = 600;
1333                 fb_vmode.refresh = 60;
1334                 default_vmode = fb_find_nearest_mode(&fb_vmode,
1335                                                      &info->modelist);
1336         }
1337
1338         /* If we have good mode and no active clients*/
1339         if ((default_vmode != NULL) && (dev->fb_count == 0)) {
1340
1341                 fb_videomode_to_var(&info->var, default_vmode);
1342                 dlfb_var_color_format(&info->var);
1343
1344                 /*
1345                  * with mode size info, we can now alloc our framebuffer.
1346                  */
1347                 memcpy(&info->fix, &dlfb_fix, sizeof(dlfb_fix));
1348                 info->fix.line_length = info->var.xres *
1349                         (info->var.bits_per_pixel / 8);
1350
1351                 result = dlfb_realloc_framebuffer(dev, info);
1352
1353         } else
1354                 result = -EINVAL;
1355
1356 error:
1357         if (edid && (dev->edid != edid))
1358                 kfree(edid);
1359
1360         if (info->dev)
1361                 mutex_unlock(&info->lock);
1362
1363         return result;
1364 }
1365
1366 static ssize_t metrics_bytes_rendered_show(struct device *fbdev,
1367                                    struct device_attribute *a, char *buf) {
1368         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1369         struct dlfb_data *dev = fb_info->par;
1370         return snprintf(buf, PAGE_SIZE, "%u\n",
1371                         atomic_read(&dev->bytes_rendered));
1372 }
1373
1374 static ssize_t metrics_bytes_identical_show(struct device *fbdev,
1375                                    struct device_attribute *a, char *buf) {
1376         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1377         struct dlfb_data *dev = fb_info->par;
1378         return snprintf(buf, PAGE_SIZE, "%u\n",
1379                         atomic_read(&dev->bytes_identical));
1380 }
1381
1382 static ssize_t metrics_bytes_sent_show(struct device *fbdev,
1383                                    struct device_attribute *a, char *buf) {
1384         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1385         struct dlfb_data *dev = fb_info->par;
1386         return snprintf(buf, PAGE_SIZE, "%u\n",
1387                         atomic_read(&dev->bytes_sent));
1388 }
1389
1390 static ssize_t metrics_cpu_kcycles_used_show(struct device *fbdev,
1391                                    struct device_attribute *a, char *buf) {
1392         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1393         struct dlfb_data *dev = fb_info->par;
1394         return snprintf(buf, PAGE_SIZE, "%u\n",
1395                         atomic_read(&dev->cpu_kcycles_used));
1396 }
1397
1398 static ssize_t edid_show(
1399                         struct file *filp,
1400                         struct kobject *kobj, struct bin_attribute *a,
1401                          char *buf, loff_t off, size_t count) {
1402         struct device *fbdev = container_of(kobj, struct device, kobj);
1403         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1404         struct dlfb_data *dev = fb_info->par;
1405
1406         if (dev->edid == NULL)
1407                 return 0;
1408
1409         if ((off >= dev->edid_size) || (count > dev->edid_size))
1410                 return 0;
1411
1412         if (off + count > dev->edid_size)
1413                 count = dev->edid_size - off;
1414
1415         pr_info("sysfs edid copy %p to %p, %d bytes\n",
1416                 dev->edid, buf, (int) count);
1417
1418         memcpy(buf, dev->edid, count);
1419
1420         return count;
1421 }
1422
1423 static ssize_t edid_store(
1424                         struct file *filp,
1425                         struct kobject *kobj, struct bin_attribute *a,
1426                         char *src, loff_t src_off, size_t src_size) {
1427         struct device *fbdev = container_of(kobj, struct device, kobj);
1428         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1429         struct dlfb_data *dev = fb_info->par;
1430
1431         /* We only support write of entire EDID at once, no offset*/
1432         if ((src_size != EDID_LENGTH) || (src_off != 0))
1433                 return 0;
1434
1435         dlfb_setup_modes(dev, fb_info, src, src_size);
1436
1437         if (dev->edid && (memcmp(src, dev->edid, src_size) == 0)) {
1438                 pr_info("sysfs written EDID is new default\n");
1439                 dlfb_ops_set_par(fb_info);
1440                 return src_size;
1441         } else
1442                 return 0;
1443 }
1444
1445 static ssize_t metrics_reset_store(struct device *fbdev,
1446                            struct device_attribute *attr,
1447                            const char *buf, size_t count)
1448 {
1449         struct fb_info *fb_info = dev_get_drvdata(fbdev);
1450         struct dlfb_data *dev = fb_info->par;
1451
1452         atomic_set(&dev->bytes_rendered, 0);
1453         atomic_set(&dev->bytes_identical, 0);
1454         atomic_set(&dev->bytes_sent, 0);
1455         atomic_set(&dev->cpu_kcycles_used, 0);
1456
1457         return count;
1458 }
1459
1460 static struct bin_attribute edid_attr = {
1461         .attr.name = "edid",
1462         .attr.mode = 0666,
1463         .size = EDID_LENGTH,
1464         .read = edid_show,
1465         .write = edid_store
1466 };
1467
1468 static struct device_attribute fb_device_attrs[] = {
1469         __ATTR_RO(metrics_bytes_rendered),
1470         __ATTR_RO(metrics_bytes_identical),
1471         __ATTR_RO(metrics_bytes_sent),
1472         __ATTR_RO(metrics_cpu_kcycles_used),
1473         __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store),
1474 };
1475
1476 /*
1477  * This is necessary before we can communicate with the display controller.
1478  */
1479 static int dlfb_select_std_channel(struct dlfb_data *dev)
1480 {
1481         int ret;
1482         u8 set_def_chn[] = {       0x57, 0xCD, 0xDC, 0xA7,
1483                                 0x1C, 0x88, 0x5E, 0x15,
1484                                 0x60, 0xFE, 0xC6, 0x97,
1485                                 0x16, 0x3D, 0x47, 0xF2  };
1486
1487         ret = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1488                         NR_USB_REQUEST_CHANNEL,
1489                         (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
1490                         set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
1491         return ret;
1492 }
1493
1494 static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
1495                                         struct usb_interface *interface)
1496 {
1497         char *desc;
1498         char *buf;
1499         char *desc_end;
1500
1501         int total_len = 0;
1502
1503         buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
1504         if (!buf)
1505                 return false;
1506         desc = buf;
1507
1508         total_len = usb_get_descriptor(interface_to_usbdev(interface),
1509                                         0x5f, /* vendor specific */
1510                                         0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
1511
1512         /* if not found, look in configuration descriptor */
1513         if (total_len < 0) {
1514                 if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
1515                         0x5f, &desc))
1516                         total_len = (int) desc[0];
1517         }
1518
1519         if (total_len > 5) {
1520                 pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
1521                         "%02x %02x %02x %02x %02x %02x %02x\n",
1522                         total_len, desc[0],
1523                         desc[1], desc[2], desc[3], desc[4], desc[5], desc[6],
1524                         desc[7], desc[8], desc[9], desc[10]);
1525
1526                 if ((desc[0] != total_len) || /* descriptor length */
1527                     (desc[1] != 0x5f) ||   /* vendor descriptor type */
1528                     (desc[2] != 0x01) ||   /* version (2 bytes) */
1529                     (desc[3] != 0x00) ||
1530                     (desc[4] != total_len - 2)) /* length after type */
1531                         goto unrecognized;
1532
1533                 desc_end = desc + total_len;
1534                 desc += 5; /* the fixed header we've already parsed */
1535
1536                 while (desc < desc_end) {
1537                         u8 length;
1538                         u16 key;
1539
1540                         key = *((u16 *) desc);
1541                         desc += sizeof(u16);
1542                         length = *desc;
1543                         desc++;
1544
1545                         switch (key) {
1546                         case 0x0200: { /* max_area */
1547                                 u32 max_area;
1548                                 max_area = le32_to_cpu(*((u32 *)desc));
1549                                 pr_warn("DL chip limited to %d pixel modes\n",
1550                                         max_area);
1551                                 dev->sku_pixel_limit = max_area;
1552                                 break;
1553                         }
1554                         default:
1555                                 break;
1556                         }
1557                         desc += length;
1558                 }
1559         } else {
1560                 pr_info("vendor descriptor not available (%d)\n", total_len);
1561         }
1562
1563         goto success;
1564
1565 unrecognized:
1566         /* allow udlfb to load for now even if firmware unrecognized */
1567         pr_err("Unrecognized vendor firmware descriptor\n");
1568
1569 success:
1570         kfree(buf);
1571         return true;
1572 }
1573 static int dlfb_usb_probe(struct usb_interface *interface,
1574                         const struct usb_device_id *id)
1575 {
1576         struct usb_device *usbdev;
1577         struct dlfb_data *dev = 0;
1578         struct fb_info *info = 0;
1579         int retval = -ENOMEM;
1580         int i;
1581
1582         /* usb initialization */
1583
1584         usbdev = interface_to_usbdev(interface);
1585
1586         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1587         if (dev == NULL) {
1588                 err("dlfb_usb_probe: failed alloc of dev struct\n");
1589                 goto error;
1590         }
1591
1592         /* we need to wait for both usb and fbdev to spin down on disconnect */
1593         kref_init(&dev->kref); /* matching kref_put in usb .disconnect fn */
1594         kref_get(&dev->kref); /* matching kref_put in free_framebuffer_work */
1595
1596         dev->udev = usbdev;
1597         dev->gdev = &usbdev->dev; /* our generic struct device * */
1598         usb_set_intfdata(interface, dev);
1599
1600         pr_info("%s %s - serial #%s\n",
1601                 usbdev->manufacturer, usbdev->product, usbdev->serial);
1602         pr_info("vid_%04x&pid_%04x&rev_%04x driver's dlfb_data struct at %p\n",
1603                 usbdev->descriptor.idVendor, usbdev->descriptor.idProduct,
1604                 usbdev->descriptor.bcdDevice, dev);
1605         pr_info("console enable=%d\n", console);
1606         pr_info("fb_defio enable=%d\n", fb_defio);
1607         pr_info("shadow enable=%d\n", shadow);
1608
1609         dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
1610
1611         if (!dlfb_parse_vendor_descriptor(dev, interface)) {
1612                 pr_err("firmware not recognized. Assume incompatible device\n");
1613                 goto error;
1614         }
1615
1616         if (!dlfb_alloc_urb_list(dev, WRITES_IN_FLIGHT, MAX_TRANSFER)) {
1617                 retval = -ENOMEM;
1618                 pr_err("dlfb_alloc_urb_list failed\n");
1619                 goto error;
1620         }
1621
1622         /* We don't register a new USB class. Our client interface is fbdev */
1623
1624         /* allocates framebuffer driver structure, not framebuffer memory */
1625         info = framebuffer_alloc(0, &interface->dev);
1626         if (!info) {
1627                 retval = -ENOMEM;
1628                 pr_err("framebuffer_alloc failed\n");
1629                 goto error;
1630         }
1631
1632         dev->info = info;
1633         info->par = dev;
1634         info->pseudo_palette = dev->pseudo_palette;
1635         info->fbops = &dlfb_ops;
1636
1637         retval = fb_alloc_cmap(&info->cmap, 256, 0);
1638         if (retval < 0) {
1639                 pr_err("fb_alloc_cmap failed %x\n", retval);
1640                 goto error;
1641         }
1642
1643         INIT_DELAYED_WORK(&dev->free_framebuffer_work,
1644                           dlfb_free_framebuffer_work);
1645
1646         INIT_LIST_HEAD(&info->modelist);
1647
1648         retval = dlfb_setup_modes(dev, info, NULL, 0);
1649         if (retval != 0) {
1650                 pr_err("unable to find common mode for display and adapter\n");
1651                 goto error;
1652         }
1653
1654         /* ready to begin using device */
1655
1656         atomic_set(&dev->usb_active, 1);
1657         dlfb_select_std_channel(dev);
1658
1659         dlfb_ops_check_var(&info->var, info);
1660         dlfb_ops_set_par(info);
1661
1662         retval = register_framebuffer(info);
1663         if (retval < 0) {
1664                 pr_err("register_framebuffer failed %d\n", retval);
1665                 goto error;
1666         }
1667
1668         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) {
1669                 retval = device_create_file(info->dev, &fb_device_attrs[i]);
1670                 if (retval) {
1671                         pr_err("device_create_file failed %d\n", retval);
1672                         goto err_del_attrs;
1673                 }
1674         }
1675
1676         retval = device_create_bin_file(info->dev, &edid_attr);
1677         if (retval) {
1678                 pr_err("device_create_bin_file failed %d\n", retval);
1679                 goto err_del_attrs;
1680         }
1681
1682         pr_info("DisplayLink USB device /dev/fb%d attached. %dx%d resolution."
1683                         " Using %dK framebuffer memory\n", info->node,
1684                         info->var.xres, info->var.yres,
1685                         ((dev->backing_buffer) ?
1686                         info->fix.smem_len * 2 : info->fix.smem_len) >> 10);
1687         return 0;
1688
1689 err_del_attrs:
1690         for (i -= 1; i >= 0; i--)
1691                 device_remove_file(info->dev, &fb_device_attrs[i]);
1692
1693 error:
1694         if (dev) {
1695
1696                 if (info) {
1697                         if (info->cmap.len != 0)
1698                                 fb_dealloc_cmap(&info->cmap);
1699                         if (info->monspecs.modedb)
1700                                 fb_destroy_modedb(info->monspecs.modedb);
1701                         if (info->screen_base)
1702                                 vfree(info->screen_base);
1703
1704                         fb_destroy_modelist(&info->modelist);
1705
1706                         framebuffer_release(info);
1707                 }
1708
1709                 if (dev->backing_buffer)
1710                         vfree(dev->backing_buffer);
1711
1712                 kref_put(&dev->kref, dlfb_free); /* ref for framebuffer */
1713                 kref_put(&dev->kref, dlfb_free); /* last ref from kref_init */
1714
1715                 /* dev has been deallocated. Do not dereference */
1716         }
1717
1718         return retval;
1719 }
1720
1721 static void dlfb_usb_disconnect(struct usb_interface *interface)
1722 {
1723         struct dlfb_data *dev;
1724         struct fb_info *info;
1725         int i;
1726
1727         dev = usb_get_intfdata(interface);
1728         info = dev->info;
1729
1730         pr_info("USB disconnect starting\n");
1731
1732         /* we virtualize until all fb clients release. Then we free */
1733         dev->virtualized = true;
1734
1735         /* When non-active we'll update virtual framebuffer, but no new urbs */
1736         atomic_set(&dev->usb_active, 0);
1737
1738         /* remove udlfb's sysfs interfaces */
1739         for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++)
1740                 device_remove_file(info->dev, &fb_device_attrs[i]);
1741         device_remove_bin_file(info->dev, &edid_attr);
1742
1743         usb_set_intfdata(interface, NULL);
1744
1745         /* if clients still have us open, will be freed on last close */
1746         if (dev->fb_count == 0)
1747                 schedule_delayed_work(&dev->free_framebuffer_work, 0);
1748
1749         /* release reference taken by kref_init in probe() */
1750         kref_put(&dev->kref, dlfb_free);
1751
1752         /* consider dlfb_data freed */
1753
1754         return;
1755 }
1756
1757 static struct usb_driver dlfb_driver = {
1758         .name = "udlfb",
1759         .probe = dlfb_usb_probe,
1760         .disconnect = dlfb_usb_disconnect,
1761         .id_table = id_table,
1762 };
1763
1764 static int __init dlfb_module_init(void)
1765 {
1766         int res;
1767
1768         res = usb_register(&dlfb_driver);
1769         if (res)
1770                 err("usb_register failed. Error number %d", res);
1771
1772         return res;
1773 }
1774
1775 static void __exit dlfb_module_exit(void)
1776 {
1777         usb_deregister(&dlfb_driver);
1778 }
1779
1780 module_init(dlfb_module_init);
1781 module_exit(dlfb_module_exit);
1782
1783 static void dlfb_urb_completion(struct urb *urb)
1784 {
1785         struct urb_node *unode = urb->context;
1786         struct dlfb_data *dev = unode->dev;
1787         unsigned long flags;
1788
1789         /* sync/async unlink faults aren't errors */
1790         if (urb->status) {
1791                 if (!(urb->status == -ENOENT ||
1792                     urb->status == -ECONNRESET ||
1793                     urb->status == -ESHUTDOWN)) {
1794                         pr_err("%s - nonzero write bulk status received: %d\n",
1795                                 __func__, urb->status);
1796                         atomic_set(&dev->lost_pixels, 1);
1797                 }
1798         }
1799
1800         urb->transfer_buffer_length = dev->urbs.size; /* reset to actual */
1801
1802         spin_lock_irqsave(&dev->urbs.lock, flags);
1803         list_add_tail(&unode->entry, &dev->urbs.list);
1804         dev->urbs.available++;
1805         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1806
1807         /*
1808          * When using fb_defio, we deadlock if up() is called
1809          * while another is waiting. So queue to another process.
1810          */
1811         if (fb_defio)
1812                 schedule_delayed_work(&unode->release_urb_work, 0);
1813         else
1814                 up(&dev->urbs.limit_sem);
1815 }
1816
1817 static void dlfb_free_urb_list(struct dlfb_data *dev)
1818 {
1819         int count = dev->urbs.count;
1820         struct list_head *node;
1821         struct urb_node *unode;
1822         struct urb *urb;
1823         int ret;
1824         unsigned long flags;
1825
1826         pr_notice("Waiting for completes and freeing all render urbs\n");
1827
1828         /* keep waiting and freeing, until we've got 'em all */
1829         while (count--) {
1830
1831                 /* Getting interrupted means a leak, but ok at shutdown*/
1832                 ret = down_interruptible(&dev->urbs.limit_sem);
1833                 if (ret)
1834                         break;
1835
1836                 spin_lock_irqsave(&dev->urbs.lock, flags);
1837
1838                 node = dev->urbs.list.next; /* have reserved one with sem */
1839                 list_del_init(node);
1840
1841                 spin_unlock_irqrestore(&dev->urbs.lock, flags);
1842
1843                 unode = list_entry(node, struct urb_node, entry);
1844                 urb = unode->urb;
1845
1846                 /* Free each separately allocated piece */
1847                 usb_free_coherent(urb->dev, dev->urbs.size,
1848                                   urb->transfer_buffer, urb->transfer_dma);
1849                 usb_free_urb(urb);
1850                 kfree(node);
1851         }
1852
1853 }
1854
1855 static int dlfb_alloc_urb_list(struct dlfb_data *dev, int count, size_t size)
1856 {
1857         int i = 0;
1858         struct urb *urb;
1859         struct urb_node *unode;
1860         char *buf;
1861
1862         spin_lock_init(&dev->urbs.lock);
1863
1864         dev->urbs.size = size;
1865         INIT_LIST_HEAD(&dev->urbs.list);
1866
1867         while (i < count) {
1868                 unode = kzalloc(sizeof(struct urb_node), GFP_KERNEL);
1869                 if (!unode)
1870                         break;
1871                 unode->dev = dev;
1872
1873                 INIT_DELAYED_WORK(&unode->release_urb_work,
1874                           dlfb_release_urb_work);
1875
1876                 urb = usb_alloc_urb(0, GFP_KERNEL);
1877                 if (!urb) {
1878                         kfree(unode);
1879                         break;
1880                 }
1881                 unode->urb = urb;
1882
1883                 buf = usb_alloc_coherent(dev->udev, MAX_TRANSFER, GFP_KERNEL,
1884                                          &urb->transfer_dma);
1885                 if (!buf) {
1886                         kfree(unode);
1887                         usb_free_urb(urb);
1888                         break;
1889                 }
1890
1891                 /* urb->transfer_buffer_length set to actual before submit */
1892                 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 1),
1893                         buf, size, dlfb_urb_completion, unode);
1894                 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1895
1896                 list_add_tail(&unode->entry, &dev->urbs.list);
1897
1898                 i++;
1899         }
1900
1901         sema_init(&dev->urbs.limit_sem, i);
1902         dev->urbs.count = i;
1903         dev->urbs.available = i;
1904
1905         pr_notice("allocated %d %d byte urbs\n", i, (int) size);
1906
1907         return i;
1908 }
1909
1910 static struct urb *dlfb_get_urb(struct dlfb_data *dev)
1911 {
1912         int ret = 0;
1913         struct list_head *entry;
1914         struct urb_node *unode;
1915         struct urb *urb = NULL;
1916         unsigned long flags;
1917
1918         /* Wait for an in-flight buffer to complete and get re-queued */
1919         ret = down_timeout(&dev->urbs.limit_sem, GET_URB_TIMEOUT);
1920         if (ret) {
1921                 atomic_set(&dev->lost_pixels, 1);
1922                 pr_warn("wait for urb interrupted: %x available: %d\n",
1923                        ret, dev->urbs.available);
1924                 goto error;
1925         }
1926
1927         spin_lock_irqsave(&dev->urbs.lock, flags);
1928
1929         BUG_ON(list_empty(&dev->urbs.list)); /* reserved one with limit_sem */
1930         entry = dev->urbs.list.next;
1931         list_del_init(entry);
1932         dev->urbs.available--;
1933
1934         spin_unlock_irqrestore(&dev->urbs.lock, flags);
1935
1936         unode = list_entry(entry, struct urb_node, entry);
1937         urb = unode->urb;
1938
1939 error:
1940         return urb;
1941 }
1942
1943 static int dlfb_submit_urb(struct dlfb_data *dev, struct urb *urb, size_t len)
1944 {
1945         int ret;
1946
1947         BUG_ON(len > dev->urbs.size);
1948
1949         urb->transfer_buffer_length = len; /* set to actual payload len */
1950         ret = usb_submit_urb(urb, GFP_KERNEL);
1951         if (ret) {
1952                 dlfb_urb_completion(urb); /* because no one else will */
1953                 atomic_set(&dev->lost_pixels, 1);
1954                 pr_err("usb_submit_urb error %x\n", ret);
1955         }
1956         return ret;
1957 }
1958
1959 module_param(console, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1960 MODULE_PARM_DESC(console, "Allow fbcon to open framebuffer");
1961
1962 module_param(fb_defio, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1963 MODULE_PARM_DESC(fb_defio, "Page fault detection of mmap writes");
1964
1965 module_param(shadow, bool, S_IWUSR | S_IRUSR | S_IWGRP | S_IRGRP);
1966 MODULE_PARM_DESC(shadow, "Shadow vid mem. Disable to save mem but lose perf");
1967
1968 MODULE_AUTHOR("Roberto De Ioris <roberto@unbit.it>, "
1969               "Jaya Kumar <jayakumar.lkml@gmail.com>, "
1970               "Bernie Thompson <bernie@plugable.com>");
1971 MODULE_DESCRIPTION("DisplayLink kernel framebuffer driver");
1972 MODULE_LICENSE("GPL");
1973