[PATCH 5.14 141/334] drm/amd/pm: Fix a bug in semaphore double-lock

Greg Kroah-Hartman
2021-09-13T14:35:04Z

From: Luben Tuikov <luben.tuikov@amd.com>

[ Upstream commit 544dcd74b7093ad4befac99b11d90331aa73348e ]

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: 5810323ba69289 ("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 | 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 a0e2111eb783..415be74df28c 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;
Out:
- mutex_unlock(&smu->message_lock);
return res;
}

--
2.30.2