drm/amd/pm: Fix a bug in semaphore double-lock

[ Upstream commit 544dcd7 ]

Fix a bug in smu_cmn_send_msg_without_waiting() in
that this function does not need to take the
smu->message_lock mutex in order to send a message
down to the SMU. The mutex is acquired by the
caller of this function instead.

Cc: Alex Deucher <Alexander.Deucher@amd.com>
Cc: Changfeng Zhu <Changfeng.Zhu@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Fixes: 5810323 ("drm/amd/pm: Fix a bug communicating with the SMU (v5)")
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Reviewed-by: Alex Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c

@@ -259,7 +259,6 @@ int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
 	if (smu->adev->no_hw_access)
 		return 0;
 
-	mutex_lock(&smu->message_lock);
 	reg = __smu_cmn_poll_stat(smu);
 	res = __smu_cmn_reg2errno(smu, reg);
 	if (reg == SMU_RESP_NONE ||
@@ -269,7 +268,6 @@ int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
 	__smu_cmn_send_msg(smu, msg_index, param);
 	res = 0;
 Out:
-	mutex_unlock(&smu->message_lock);
 	return res;
 }