From d5c9ade755a9afa210840708a12a8f44c0d532f4 Mon Sep 17 00:00:00 2001 From: Wayne Lin Date: Fri, 18 Apr 2025 16:31:59 +0800 Subject: [PATCH] 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 Cc: Alex Deucher Reviewed-by: Ray Wu Signed-off-by: Wayne Lin Signed-off-by: Ray Wu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- 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 f531bb3bf3d3..31894e52f307 100644 --- 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)) {