From: Wayne Lin Wayne.Lin@amd.com

[ Upstream commit ef67d792a2fc578319399f605fbec2f99ecc06ea ]

[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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 28a6c7b2ef4bb..2f858507ca702 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 @@ -101,7 +101,7 @@ 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)