drm: work around EDIDs with bad htotal/vtotal values

We did this on the userspace side, but we need a similar fix for the
kernel.

Fixes LP #460664.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_edid.c

@@ -662,6 +662,12 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_device *dev,
 		return NULL;
 	}
 
+	/* Some EDIDs have bogus h/vtotal values */
+	if (mode->hsync_end > mode->htotal)
+		mode->htotal = mode->hsync_end + 1;
+	if (mode->vsync_end > mode->vtotal)
+		mode->vtotal = mode->vsync_end + 1;
+
 	drm_mode_set_name(mode);
 
 	if (pt->misc & DRM_EDID_PT_INTERLACED)