On Wed, 30 Mar 2016, Ville Syrjälä ville.syrjala@linux.intel.com wrote:

On Sat, Mar 26, 2016 at 01:18:38PM +0000, Paul Parsons wrote:

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The EDID 1.4 specification section 3.10.3.9 defines an Established Timings III descriptor (tag #F7h). The parsing of this descriptor by drm_est3_modes() is off by one byte: the offset of the first timing bitmap is 6, not 5.

Signed-off-by: Paul Parsons lost.distance@yahoo.com

diff -ru a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c --- a/drivers/gpu/drm/drm_edid.c 2016-03-14 04:28:54.000000000 +0000 +++ b/drivers/gpu/drm/drm_edid.c 2016-03-26 12:04:58.963352156 +0000 @@ -2215,7 +2215,7 @@ { int i, j, m, modes = 0; struct drm_display_mode *mode;

• u8 *est = ((u8 *)timing) + 5;

• u8 *est = ((u8 *)timing) + 6;

Hmm. The code is very hard to follow due to the weird structs and whatnot. But yeah this looks correct.

Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com

Pushed to our topic/drm-fixes, thanks for the patch and review.

BR, Jani.

Oh and I suppose you could also fix up the EDID version check to check for 1.4+ before even considering the est3 descriptor as valid.

...

for (i = 0; i < 6; i++) { for (j = 7; j >= 0; j--) {

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