drm/amd/display: Properly reuse completion structure

commit 0cf8307adbc6beb5ff3b8a76afedc6e4e0b536a9 upstream.

[Why]
Connecting displays to TBT3 docks often produces invalid
replies for DPIA AUX requests. It turns out the completion
structure was not re-initialized before reusing it, resulting
in immature wake up to completion.

[How]
Properly call reinit_completion() on reused completion structure.

Cc: stable@vger.kernel.org
Reviewed-by: Solomon Chiu <solomon.chiu@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: "Limonciello, Mario" <mario.limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 b707593..a930b18 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -10251,6 +10251,7 @@ int amdgpu_dm_process_dmub_aux_transfer_sync(
        ret = p_notify->aux_reply.length;
        *operation_result = p_notify->result;
 out:
+       reinit_completion(&adev->dm.dmub_aux_transfer_done);
        mutex_unlock(&adev->dm.dpia_aux_lock);
        return ret;
 }
@@ -10278,6 +10279,8 @@ int amdgpu_dm_process_dmub_set_config_sync(
                *operation_result = SET_CONFIG_UNKNOWN_ERROR;
        }
 
+       if (!is_cmd_complete)
+               reinit_completion(&adev->dm.dmub_aux_transfer_done);
        mutex_unlock(&adev->dm.dpia_aux_lock);
        return ret;
 }