fbdev: fix parsing of standard timings

The standard timings parses uses 1:1 dimensions when the ratio in the
EDID data is 0. However, for EDID 1.3 and later the dimensions are 16:10
when the ratio is 0.

Pass the version and revision numbers to get_std_timing() which can then
make the right decision about dimensions.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c
index 4f57485..cef6557 100644 (file)
--- a/drivers/video/fbmon.c
+++ b/drivers/video/fbmon.c
@@ -493,7 +493,8 @@ static int get_est_timing(unsigned char *block, struct fb_videomode *mode)
        return num;
 }
 
-static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
+static int get_std_timing(unsigned char *block, struct fb_videomode *mode,
+               int ver, int rev)
 {
        int xres, yres = 0, refresh, ratio, i;
 
@@ -504,7 +505,11 @@ static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
        ratio = (block[1] & 0xc0) >> 6;
        switch (ratio) {
        case 0:
-               yres = xres;
+               /* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */
+               if (ver < 1 || (ver == 1 && rev < 3))
+                       yres = xres;
+               else
+                       yres = (xres * 10)/16;
                break;
        case 1:
                yres = (xres * 3)/4;
@@ -533,12 +538,12 @@ static int get_std_timing(unsigned char *block, struct fb_videomode *mode)
 }
 
 static int get_dst_timing(unsigned char *block,
-                         struct fb_videomode *mode)
+                         struct fb_videomode *mode, int ver, int rev)
 {
        int j, num = 0;
 
        for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE)
-               num += get_std_timing(block, &mode[num]);
+               num += get_std_timing(block, &mode[num], ver, rev);
 
        return num;
 }
@@ -599,6 +604,10 @@ static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
        struct fb_videomode *mode, *m;
        unsigned char *block;
        int num = 0, i, first = 1;
+       int ver, rev;
+
+       ver = edid[EDID_STRUCT_VERSION];
+       rev = edid[EDID_STRUCT_REVISION];
 
        mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
        if (mode == NULL)
@@ -632,12 +641,12 @@ static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize)
        DPRINTK("   Standard Timings\n");
        block = edid + STD_TIMING_DESCRIPTIONS_START;
        for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE)
-               num += get_std_timing(block, &mode[num]);
+               num += get_std_timing(block, &mode[num], ver, rev);
 
        block = edid + DETAILED_TIMING_DESCRIPTIONS_START;
        for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) {
                if (block[0] == 0x00 && block[1] == 0x00 && block[3] == 0xfa)
-                       num += get_dst_timing(block + 5, &mode[num]);
+                       num += get_dst_timing(block + 5, &mode[num], ver, rev);
        }
 
        /* Yikes, EDID data is totally useless */