[PATCH 22/28] drm/amd/display: Shift DMUB AUX reply command if necessary

[PATCH 22/28] drm/amd/display: Shift DMUB AUX reply command if necessary

[Ray Wu]

From: Wayne Lin <Wayne.Lin@amd.com>

[Why]
Defined value of dmub AUX reply command field get updated but didn't
adjust dm receiving side accordingly.

[How]
Check the received reply command value to see if it's updated version
or not. Adjust it if necessary.

Fixes: ead08b95fa50 ("drm/amd/display: Fix race condition in DPIA AUX transfer")
Cc: stable@vger.kernel.org
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

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 cd6e7aa91040..a59d0ff999e9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -12852,8 +12852,11 @@ int amdgpu_dm_process_dmub_aux_transfer_sync(
 		goto out;
 	}
 
+	payload->reply[0] = adev->dm.dmub_notify->aux_reply.command & 0xF;
+	if (adev->dm.dmub_notify->aux_reply.command & 0xF0)
+		/* The reply is stored in the top nibble of the command. */
+		payload->reply[0] = (adev->dm.dmub_notify->aux_reply.command >> 4) & 0xF;
 
-	payload->reply[0] = adev->dm.dmub_notify->aux_reply.command;
 	if (!payload->write && p_notify->aux_reply.length &&
 			(payload->reply[0] == AUX_TRANSACTION_REPLY_AUX_ACK)) {
 
-- 
2.43.0

[PATCH 24/28] drm/amd/display: Remove incorrect checking in dmub aux handler

[Ray Wu]

From: Wayne Lin <Wayne.Lin@amd.com>

[Why & How]
"Request length != reply length" is expected behavior defined in spec.
It's not an invalid reply. Besides, replied data handling logic is not
designed to be written in amdgpu_dm_process_dmub_aux_transfer_sync().
Remove the incorrectly handling section.

Fixes: ead08b95fa50 ("drm/amd/display: Fix race condition in DPIA AUX transfer")
Cc: stable@vger.kernel.org
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

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 ae71ff3d87a7..d9c18e0f7395 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -12858,19 +12858,9 @@ int amdgpu_dm_process_dmub_aux_transfer_sync(
 		payload->reply[0] = (adev->dm.dmub_notify->aux_reply.command >> 4) & 0xF;
 
 	if (!payload->write && p_notify->aux_reply.length &&
-			(payload->reply[0] == AUX_TRANSACTION_REPLY_AUX_ACK)) {
-
-		if (payload->length != p_notify->aux_reply.length) {
-			drm_warn(adev_to_drm(adev), "invalid read length %d from DPIA AUX 0x%x(%d)!\n",
-				p_notify->aux_reply.length,
-					payload->address, payload->length);
-			*operation_result = AUX_RET_ERROR_INVALID_REPLY;
-			goto out;
-		}
-
+			(payload->reply[0] == AUX_TRANSACTION_REPLY_AUX_ACK))
 		memcpy(payload->data, p_notify->aux_reply.data,
 				p_notify->aux_reply.length);
-	}
 
 	/* success */
 	ret = p_notify->aux_reply.length;
-- 
2.43.0

[PATCH 25/28] drm/amd/display: Copy AUX read reply data whenever length > 0

[Ray Wu]

From: Wayne Lin <Wayne.Lin@amd.com>

[Why]
amdgpu_dm_process_dmub_aux_transfer_sync() should return all exact data
reply from the sink side. Don't do the analysis job in it.

[How]
Remove unnecessary check condition AUX_TRANSACTION_REPLY_AUX_ACK.

Fixes: ead08b95fa50 ("drm/amd/display: Fix race condition in DPIA AUX transfer")
Cc: stable@vger.kernel.org
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

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 d9c18e0f7395..88b390609c9f 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -12857,8 +12857,7 @@ int amdgpu_dm_process_dmub_aux_transfer_sync(
 		/* The reply is stored in the top nibble of the command. */
 		payload->reply[0] = (adev->dm.dmub_notify->aux_reply.command >> 4) & 0xF;
 
-	if (!payload->write && p_notify->aux_reply.length &&
-			(payload->reply[0] == AUX_TRANSACTION_REPLY_AUX_ACK))
+	if (!payload->write && p_notify->aux_reply.length)
 		memcpy(payload->data, p_notify->aux_reply.data,
 				p_notify->aux_reply.length);
 
-- 
2.43.0

[PATCH 26/28] drm/amd/display: Fix wrong handling for AUX_DEFER case

[Ray Wu]

From: Wayne Lin <Wayne.Lin@amd.com>

[Why]
We incorrectly ack all bytes get written when the reply actually is defer.
When it's defer, means sink is not ready for the request. We should
retry the request.

[How]
Only reply all data get written when receive I2C_ACK|AUX_ACK. Otherwise,
reply the number of actual written bytes received from the sink.
Add some messages to facilitate debugging as well.

Fixes: ad6756b4d773 ("drm/amd/display: Shift dc link aux to aux_payload")
Cc: stable@vger.kernel.org
Reviewed-by: Ray Wu <ray.wu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
---
 .../display/amdgpu_dm/amdgpu_dm_mst_types.c   | 28 ++++++++++++++++---
 1 file changed, 24 insertions(+), 4 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 d8dcfb3efaaa..d19aea595722 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
@@ -51,6 +51,9 @@
 
 #define PEAK_FACTOR_X1000 1006
 
+/*
+ * This function handles both native AUX and I2C-Over-AUX transactions.
+ */
 static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
 				  struct drm_dp_aux_msg *msg)
 {
@@ -87,15 +90,25 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
 	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;
+			result = msg->size;
 			operation_result = AUX_RET_SUCCESS;
 		}
 	}
 
-	if (payload.write && result >= 0)
-		result = msg->size;
+	/*
+	 * result equals to 0 includes the cases of AUX_DEFER/I2C_DEFER
+	 */
+	if (payload.write && result >= 0) {
+		if (result) {
+			/*one byte indicating partially written bytes. Force 0 to retry*/
+			drm_info(adev_to_drm(adev), "amdgpu: AUX partially written\n");
+			result = 0;
+		} else if (!payload.reply[0])
+			/*I2C_ACK|AUX_ACK*/
+			result = msg->size;
+	}
 
-	if (result < 0)
+	if (result < 0) {
 		switch (operation_result) {
 		case AUX_RET_SUCCESS:
 			break;
@@ -114,6 +127,13 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
 			break;
 		}
 
+		drm_info(adev_to_drm(adev), "amdgpu: DP AUX transfer fail:%d\n", operation_result);
+	}
+
+	if (payload.reply[0])
+		drm_info(adev_to_drm(adev), "amdgpu: AUX reply command not ACK: 0x%02x.",
+			payload.reply[0]);
+
 	return result;
 }
 
-- 
2.43.0