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)) {