Commit 76ac1cc7 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Zheng Zengkai
Browse files

drm/i915: Also check for VGA converter in eDP probe

stable inclusion
from stable-v6.6.5
commit 517e1355bbbe4382a0d1798b0561802c4c9be906
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8N21P

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=517e1355bbbe4382a0d1798b0561802c4c9be906

--------------------------------

commit f76f83a83c8fdbb62acbf8bd945f10821768145b upstream.

Unfortunately even the HPD based detection added in
commit cfe5bdfb ("drm/i915: Check HPD live state during eDP probe")
fails to detect that the VBT's eDP/DDI-A is a ghost on
Asus B360M-A (CFL+CNP). On that board eDP/DDI-A has its HPD
asserted despite nothing being actually connected there :(
The straps/fuses also indicate that the eDP port is present.

So if one boots with a VGA monitor connected the eDP probe will
mistake the DP->VGA converter hooked to DDI-E for an eDP panel
on DDI-A.

As a last resort check what kind of DP device we've detected,
and if it looks like a DP->VGA converter then conclude that
the eDP port should be ignored.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9636


Fixes: cfe5bdfb ("drm/i915: Check HPD live state during eDP probe")
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231114142333.15799-1-ville.syrjala@linux.intel.com


Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
(cherry picked from commit fcd479a79120bf0cd507d85f898297a3b868dda6)
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 8d595bfd
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please to comment