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authorFangzhi Zuo <Jerry.Zuo@amd.com>2022-07-06 15:52:46 -0400
committerAlex Deucher <alexander.deucher@amd.com>2022-07-13 12:20:26 -0400
commitacea108fa067d140bd155161a79b1fcd967f4137 (patch)
tree33efb0040c863689fba07dfab86cdb79631800ed /drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
parentMerge tag 'drm-misc-fixes-2022-07-07-1' of ssh://git.freedesktop.org/git/drm/drm-misc into drm-fixes (diff)
downloadlinux-dev-acea108fa067d140bd155161a79b1fcd967f4137.tar.xz
linux-dev-acea108fa067d140bd155161a79b1fcd967f4137.zip
drm/amd/display: Ignore First MST Sideband Message Return Error
[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
Diffstat (limited to '')
-rw-r--r--drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c17
1 files changed, 17 insertions, 0 deletions
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 9221b6690a4a..2b9b095e5f03 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
@@ -56,6 +56,8 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
ssize_t result = 0;
struct aux_payload payload;
enum aux_return_code_type operation_result;
+ struct amdgpu_device *adev;
+ struct ddc_service *ddc;
if (WARN_ON(msg->size > 16))
return -E2BIG;
@@ -74,6 +76,21 @@ 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);
+ /*
+ * w/a on certain intel platform where hpd is unexpected to pull low during
+ * 1st sideband message transaction by return AUX_RET_ERROR_HPD_DISCON
+ * aux transaction is succuess in such case, therefore bypass the error
+ */
+ ddc = TO_DM_AUX(aux)->ddc_service;
+ adev = ddc->ctx->driver_context;
+ if (adev->dm.aux_hpd_discon_quirk) {
+ if (msg->address == DP_SIDEBAND_MSG_DOWN_REQ_BASE &&
+ operation_result == AUX_RET_ERROR_HPD_DISCON) {
+ result = 0;
+ operation_result = AUX_RET_SUCCESS;
+ }
+ }
+
if (payload.write && result >= 0)
result = msg->size;