[ 3.5.y.z extended stable ] Patch "drm: don't add inferred modes for monitors that don't support" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    drm: don't add inferred modes for monitors that don't support

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From e673ab68219bc08230c4ed26268f28ba7588901e Mon Sep 17 00:00:00 2001
From: Paulo Zanoni <paulo.r.zanoni at intel.com>
Date: Fri, 15 Feb 2013 13:36:27 -0200
Subject: [PATCH] drm: don't add inferred modes for monitors that don't support
 them

commit 196e077dc165a307efbd9e7569f81bbdbcf18f65 upstream.

If bit 0 of the features byte (0x18) is set to 0, then, according to
the EDID spec, "the display is non-continuous frequency (multi-mode)
and is only specified to accept the video timing formats that are
listed in Base EDID and certain Extension Blocks".

For more information, please see the EDID spec, check the notes of the
table that explains the "Feature Support" byte (18h) and also the
notes on the tables of the section that explains "Display Range Limits
& Additional Timing Description Definition (tag #FDh)".

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45729
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
Reviewed-by: Adam Jackson <ajax at redhat.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Dave Airlie <airlied at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/drm_edid.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a8743c3..74f2421 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1921,7 +1921,8 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)
 	num_modes += add_cvt_modes(connector, edid);
 	num_modes += add_standard_modes(connector, edid);
 	num_modes += add_established_modes(connector, edid);
-	num_modes += add_inferred_modes(connector, edid);
+	if (edid->features & DRM_EDID_FEATURE_DEFAULT_GTF)
+		num_modes += add_inferred_modes(connector, edid);
 	num_modes += add_cea_modes(connector, edid);

 	if (quirks & (EDID_QUIRK_PREFER_LARGE_60 | EDID_QUIRK_PREFER_LARGE_75))
--
1.8.1.2