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

Luben Tuikov luben.tuikov at amd.com
Wed Jul 28 15:17:40 UTC 2021

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 at amd.com>
Cc: Changfeng Zhu <Changfeng.Zhu at amd.com>
Cc: Huang Rui <ray.huang at amd.com>
Fixes: e070ba49f3a764 ("drm/amd/pm: Fix a bug communicating with the SMU (v5)")
 drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
index a0e2111eb7838c..415be74df28c7f 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
+++ b/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;
-	mutex_unlock(&smu->message_lock);
 	return res;

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