6.14-stable review patch. If anyone has any objections, please let me know.
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From: Wayne Lin Wayne.Lin@amd.com
commit d433981385c62c72080e26f1c00a961d18b233be upstream.
[Why] Now forcing aux->transfer to return 0 when incomplete AUX write is inappropriate. It should return bytes have been transferred.
[How] aux->transfer is asked not to change original msg except reply field of drm_dp_aux_msg structure. Copy the msg->buffer when it's write request, and overwrite the first byte when sink reply 1 byte indicating partially written byte number. Then we can return the correct value without changing the original msg.
Fixes: 3637e457eb00 ("drm/amd/display: Fix wrong handling for AUX_DEFER case") 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 (cherry picked from commit 7ac37f0dcd2e0b729fa7b5513908dc8ab802b540) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 3 ++- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 10 ++++++++-- 2 files changed, 10 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -12621,7 +12621,8 @@ int amdgpu_dm_process_dmub_aux_transfer_ /* 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) + /*write req may receive a byte indicating partially written number as well*/ + if (p_notify->aux_reply.length) memcpy(payload->data, p_notify->aux_reply.data, p_notify->aux_reply.length);
--- 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 @@ -62,6 +62,7 @@ static ssize_t dm_dp_aux_transfer(struct enum aux_return_code_type operation_result; struct amdgpu_device *adev; struct ddc_service *ddc; + uint8_t copy[16];
if (WARN_ON(msg->size > 16)) return -E2BIG; @@ -77,6 +78,11 @@ static ssize_t dm_dp_aux_transfer(struct (msg->request & DP_AUX_I2C_WRITE_STATUS_UPDATE) != 0; payload.defer_delay = 0;
+ if (payload.write) { + memcpy(copy, msg->buffer, msg->size); + payload.data = copy; + } + result = dc_link_aux_transfer_raw(TO_DM_AUX(aux)->ddc_service, &payload, &operation_result);
@@ -100,9 +106,9 @@ static ssize_t dm_dp_aux_transfer(struct */ if (payload.write && result >= 0) { if (result) { - /*one byte indicating partially written bytes. Force 0 to retry*/ + /*one byte indicating partially written bytes*/ drm_info(adev_to_drm(adev), "amdgpu: AUX partially written\n"); - result = 0; + result = payload.data[0]; } else if (!payload.reply[0]) /*I2C_ACK|AUX_ACK*/ result = msg->size;