drm/amd/display: Shift DMUB AUX reply command if necessary

[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: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
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>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 f531bb3bf3d302ce9a38f0970bc6e23a5d45f3b7..31894e52f30799e4d1ee507c63c7983d5b06a202 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -12848,8 +12848,11 @@ 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)) {