USB: Fix up full-speed bInterval values in high-speed interrupt descriptor

[pandora-kernel.git] / drivers / usb / core / config.c

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 2d4fd53..5e113db 100644 (file)
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -1,4 +1,5 @@
 #include <linux/usb.h>
+#include <linux/usb/ch9.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -49,7 +50,7 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
        unsigned char *buffer0 = buffer;
        struct usb_endpoint_descriptor *d;
        struct usb_host_endpoint *endpoint;
-       int n, i;
+       int n, i, j;
 
        d = (struct usb_endpoint_descriptor *) buffer;
        buffer += d->bLength;
@@ -84,6 +85,66 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
        memcpy(&endpoint->desc, d, n);
        INIT_LIST_HEAD(&endpoint->urb_list);
 
+       /* Fix up bInterval values outside the legal range. Use 32 ms if no
+        * proper value can be guessed. */
+       i = 0;          /* i = min, j = max, n = default */
+       j = 255;
+       if (usb_endpoint_xfer_int(d)) {
+               i = 1;
+               switch (to_usb_device(ddev)->speed) {
+               case USB_SPEED_HIGH:
+                       /* Many device manufacturers are using full-speed
+                        * bInterval values in high-speed interrupt endpoint
+                        * descriptors. Try to fix those and fall back to a
+                        * 32 ms default value otherwise. */
+                       n = fls(d->bInterval*8);
+                       if (n == 0)
+                               n = 9;  /* 32 ms = 2^(9-1) uframes */
+                       j = 16;
+                       break;
+               default:                /* USB_SPEED_FULL or _LOW */
+                       /* For low-speed, 10 ms is the official minimum.
+                        * But some "overclocked" devices might want faster
+                        * polling so we'll allow it. */
+                       n = 32;
+                       break;
+               }
+       } else if (usb_endpoint_xfer_isoc(d)) {
+               i = 1;
+               j = 16;
+               switch (to_usb_device(ddev)->speed) {
+               case USB_SPEED_HIGH:
+                       n = 9;          /* 32 ms = 2^(9-1) uframes */
+                       break;
+               default:                /* USB_SPEED_FULL */
+                       n = 6;          /* 32 ms = 2^(6-1) frames */
+                       break;
+               }
+       }
+       if (d->bInterval < i || d->bInterval > j) {
+               dev_warn(ddev, "config %d interface %d altsetting %d "
+                   "endpoint 0x%X has an invalid bInterval %d, "
+                   "changing to %d\n",
+                   cfgno, inum, asnum,
+                   d->bEndpointAddress, d->bInterval, n);
+               endpoint->desc.bInterval = n;
+       }
+
+       /* Some buggy low-speed devices have Bulk endpoints, which is
+        * explicitly forbidden by the USB spec.  In an attempt to make
+        * them usable, we will try treating them as Interrupt endpoints.
+        */
+       if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
+                       usb_endpoint_xfer_bulk(d)) {
+               dev_warn(ddev, "config %d interface %d altsetting %d "
+                   "endpoint 0x%X is Bulk; changing to Interrupt\n",
+                   cfgno, inum, asnum, d->bEndpointAddress);
+               endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
+               endpoint->desc.bInterval = 1;
+               if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
+                       endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
+       }
+
        /* Skip over any Class Specific or Vendor Specific descriptors;
         * find the next endpoint or interface descriptor */
        endpoint->extra = buffer;