The patch below does not apply to the 6.8-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Thanks, Sasha

------------------ original commit in Linus's tree ------------------

From 3b84525544be4ca0481110263a6d73eb00741cf3 Mon Sep 17 00:00:00 2001 From: Wayne Lin Wayne.Lin@amd.com Date: Tue, 2 Jan 2024 14:20:37 +0800 Subject: [PATCH] drm/amd/display: Align the returned error code with legacy DP

[Why] For usb4 connector, AUX transaction is handled by dmub utilizing a differnt code path comparing to legacy DP connector. If the usb4 DP connector is disconnected, AUX access will report EBUSY and cause igt@kms_dp_aux_dev fail.

[How] Align the error code with the one reported by legacy DP as EIO.

Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Acked-by: Alex Hung alex.hung@amd.com Signed-off-by: Wayne Lin Wayne.Lin@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c index eaf8d9f482446..85b7f58a7f35a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c @@ -979,6 +979,11 @@ int dm_helper_dmub_aux_transfer_sync( struct aux_payload *payload, enum aux_return_code_type *operation_result) { + if (!link->hpd_status) { + *operation_result = AUX_RET_ERROR_HPD_DISCON; + return -1; + } + return amdgpu_dm_process_dmub_aux_transfer_sync(ctx, link->link_index, payload, operation_result); }