drm: ignore EDID with really tiny modes.

Some EDIDs lie and report tiny modes that aren't possible. Ignore
these modes.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index ca9c61656714..6f6b26479d82 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -289,6 +289,11 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
         struct drm_display_mode *mode;
         struct detailed_pixel_timing *pt = &timing->data.pixel_data;
 
+        /* ignore tiny modes */
+        if (((pt->hactive_hi << 8) | pt->hactive_lo) < 64 ||
+            ((pt->vactive_hi << 8) | pt->hactive_lo) < 64)
+                return NULL;
+
         if (pt->stereo) {
                 printk(KERN_WARNING "stereo mode not supported\n");
                 return NULL;