From ef67d792a2fc578319399f605fbec2f99ecc06ea Mon Sep 17 00:00:00 2001
From: Wayne Lin <Wayne.Lin@amd.com>
Date: Tue, 18 Aug 2020 11:19:42 +0800
Subject: [PATCH] drm/amd/display: Retry AUX write when fail occurs
Git-commit: ef67d792a2fc578319399f605fbec2f99ecc06ea
Patch-mainline: v5.9-rc3
References: git-fixes
[Why]
In dm_dp_aux_transfer() now, we forget to handle AUX_WR fail cases. We
suppose every write wil get done successfully and hence some AUX
commands might not sent out indeed.
[How]
Check if AUX_WR success. If not, retry it.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index e85b58f0f416..336aaa09be46 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -67,7 +67,7 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
result = dc_link_aux_transfer_raw(TO_DM_AUX(aux)->ddc_service, &payload,
&operation_result);
- if (payload.write)
+ if (payload.write && result >= 0)
result = msg->size;
if (result < 0)
--
2.26.2