drm/amd/display: Respect aux return values

[Why]
The new aux implementation was not up to spec. This caused us to fail DP
compliance as well as introduced serious delays during system resume.

[How]
Make dce_aux_transfer_raw return the operation result

Make dce_aux_transfer_with_retries delay with udelay instead
of msleep, and only on invalid reply.  Also fail on the second
invalid reply, third timeout, or first of any other error

Convert return values to drm error codes in amdgpu_dm

As the two aux transfer functions are now noticeably
different, change the names to better reflect their
functionality and document.

There was one last call to dc_link_aux_transfer that
should have retries, fix that

Signed-off-by: David Francis <David.Francis@amd.com>
Signed-off-by: Thomas Lim <Thomas.Lim@amd.com>
Reviewed-by: David Francis <David.Francis@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Acked-by: Eric Yang <eric.yang2@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 18 insertions, 3 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 c4ea3a91f17a..6e205ee36ac3 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
@@ -84,6 +84,7 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
 {
 	ssize_t result = 0;
 	struct aux_payload payload;
+	enum aux_channel_operation_result operation_result;
 
 	if (WARN_ON(msg->size > 16))
 		return -E2BIG;
@@ -97,13 +98,27 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
 	payload.mot = (msg->request & DP_AUX_I2C_MOT) != 0;
 	payload.defer_delay = 0;
 
-	result = dc_link_aux_transfer(TO_DM_AUX(aux)->ddc_service, &payload);
+	result = dc_link_aux_transfer_raw(TO_DM_AUX(aux)->ddc_service, &payload,
+				      &operation_result);
 
 	if (payload.write)
 		result = msg->size;
 
-	if (result < 0) /* DC doesn't know about kernel error codes */
-		result = -EIO;
+	if (result < 0)
+		switch (operation_result) {
+		case AUX_CHANNEL_OPERATION_SUCCEEDED:
+			break;
+		case AUX_CHANNEL_OPERATION_FAILED_HPD_DISCON:
+		case AUX_CHANNEL_OPERATION_FAILED_REASON_UNKNOWN:
+			result = -EIO;
+			break;
+		case AUX_CHANNEL_OPERATION_FAILED_INVALID_REPLY:
+			result = -EBUSY;
+			break;
+		case AUX_CHANNEL_OPERATION_FAILED_TIMEOUT:
+			result = -ETIMEDOUT;
+			break;
+		}
 
 	return result;
 }