The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3b2e973dff59d88bee1d814ddf8762a24fc02b60 Mon Sep 17 00:00:00 2001 From: Aaron Ma <aaron.ma@xxxxxxxxxxxxx> Date: Wed, 8 Jul 2020 04:16:22 -0400 Subject: [PATCH] drm/amd/display: add dmcub check on RENOIR RENOIR loads dmub fw not dmcu, check dmcu only will prevent loading iram, it breaks backlight control. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=208277 Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> Signed-off-by: Aaron Ma <aaron.ma@xxxxxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 10ac8076d4f2..db5e0bb0d935 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1358,7 +1358,7 @@ static int dm_late_init(void *handle) struct dmcu *dmcu = NULL; bool ret; - if (!adev->dm.fw_dmcu) + if (!adev->dm.fw_dmcu && !adev->dm.dmub_fw) return detect_mst_link_for_all_connectors(adev->ddev); dmcu = adev->dm.dc->res_pool->dmcu;
