This is a note to let you know that I've just added the patch titled drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-edid-add-6-bpc-quirk-for-cpt-panel-in-asus-ux303la.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 06998a756a3865817b87a129a7e5d5bb66dc1ec3 Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Date: Sun, 18 Feb 2018 16:53:59 +0800 Subject: drm/edid: Add 6 bpc quirk for CPT panel in Asus UX303LA From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> commit 06998a756a3865817b87a129a7e5d5bb66dc1ec3 upstream. Similar to commit e10aec652f31 ("drm/edid: Add 6 bpc quirk for display AEO model 0."), the EDID reports "DFP 1.x compliant TMDS" but it support 6bpc instead of 8 bpc. Hence, use 6 bpc quirk for this panel. Fixes: 196f954e2509 ("drm/i915/dp: Revert "drm/i915/dp: fall back to 18 bpp when sink capability is unknown"") BugLink: https://bugs.launchpad.net/bugs/1749420 Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Reviewed-by: Mario Kleiner <mario.kleiner.de@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v4.8+ Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20180218085359.7817-1-kai.heng.feng@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_edid.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -106,6 +106,9 @@ static struct edid_quirk { /* AEO model 0 reports 8 bpc, but is a 6 bpc panel */ { "AEO", 0, EDID_QUIRK_FORCE_6BPC }, + /* CPT panel of Asus UX303LA reports 8 bpc, but is a 6 bpc panel */ + { "CPT", 0x17df, EDID_QUIRK_FORCE_6BPC }, + /* Belinea 10 15 55 */ { "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 }, { "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 }, Patches currently in stable-queue which might be from kai.heng.feng@xxxxxxxxxxxxx are queue-4.4/drm-edid-add-6-bpc-quirk-for-cpt-panel-in-asus-ux303la.patch