drm/amd/display: Ignore First MST Sideband Message Return Error
authorFangzhi Zuo <Jerry.Zuo@amd.com>
Wed, 6 Jul 2022 19:52:46 +0000 (15:52 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Jul 2022 15:25:12 +0000 (17:25 +0200)
commitc7720f23bb93628f30f16d033eaefbe2540f1b5e
treeb0ad5b855018db92a819f00e3d9cf09a84255bf8
parent8bae037b0fb429466fed1585440f337396d72efa
drm/amd/display: Ignore First MST Sideband Message Return Error

[ Upstream commit acea108fa067d140bd155161a79b1fcd967f4137 ]

[why]
First MST sideband message returns AUX_RET_ERROR_HPD_DISCON
on certain intel platform. Aux transaction considered failure
if HPD unexpected pulled low. The actual aux transaction success
in such case, hence do not return error.

[how]
Not returning error when AUX_RET_ERROR_HPD_DISCON detected
on the first sideband message.

v2: squash in additional DMI entries
v3: squash in static fix

Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c