drm/edid: Skip empty CVT codepoints

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

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 5c9f79877cbf..7d6ac22f5b2d 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -911,11 +911,15 @@ static int drm_cvt_modes(struct drm_connector *connector,
         struct drm_device *dev = connector->dev;
         struct cvt_timing *cvt;
         const int rates[] = { 60, 85, 75, 60, 50 };
+        const u8 empty[3] = { 0, 0, 0 };
 
         for (i = 0; i < 4; i++) {
                 int uninitialized_var(width), height;
                 cvt = &(timing->data.other_data.data.cvt[i]);
 
+                if (!memcmp(cvt->code, empty, 3))
+                        continue;
+
                 height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 8) + 1) * 2;
                 switch (cvt->code[1] & 0xc0) {
                 case 0x00: