[PATCH 9/9] drm/amd/powerplay: added mutex protection on msg issuing

[Evan Quan]

This could avoid the possible race condition.

Change-Id: I518b6f96b1a836bda4f1c7e13c00f62cd316a90c
Signed-off-by: Evan Quan <evan.quan at amd.com>
---
 drivers/gpu/drm/amd/powerplay/amd_powerplay.c |  3 +++
 drivers/gpu/drm/amd/powerplay/inc/hwmgr.h     |  1 +
 drivers/gpu/drm/amd/powerplay/smumgr/smumgr.c | 16 ++++++++++++++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
index a7f4164fe8d4..9881e20c1119 100644
--- a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
+++ b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
@@ -50,6 +50,7 @@ static int amd_powerplay_create(struct amdgpu_device *adev)
 	hwmgr->not_vf = !amdgpu_sriov_vf(adev);
 	hwmgr->device = amdgpu_cgs_create_device(adev);
 	mutex_init(&hwmgr->smu_lock);
+	mutex_init(&hwmgr->msg_lock);
 	hwmgr->chip_family = adev->family;
 	hwmgr->chip_id = adev->asic_type;
 	hwmgr->feature_mask = adev->pm.pp_feature;
@@ -64,6 +65,8 @@ static void amd_powerplay_destroy(struct amdgpu_device *adev)
 {
 	struct pp_hwmgr *hwmgr = adev->powerplay.pp_handle;
 
+	mutex_destroy(&hwmgr->msg_lock);
+
 	kfree(hwmgr->hardcode_pp_table);
 	hwmgr->hardcode_pp_table = NULL;
 
diff --git a/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h b/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h
index 34c48b6daa46..9b8fe00bd601 100644
--- a/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h
+++ b/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h
@@ -744,6 +744,7 @@ struct pp_hwmgr {
 	bool pm_en;
 	bool pp_one_vf;
 	struct mutex smu_lock;
+	struct mutex msg_lock;
 
 	uint32_t pp_table_version;
 	void *device;
diff --git a/drivers/gpu/drm/amd/powerplay/smumgr/smumgr.c b/drivers/gpu/drm/amd/powerplay/smumgr/smumgr.c
index 3bb0392994ec..b6fb48066841 100644
--- a/drivers/gpu/drm/amd/powerplay/smumgr/smumgr.c
+++ b/drivers/gpu/drm/amd/powerplay/smumgr/smumgr.c
@@ -136,13 +136,19 @@ int smum_send_msg_to_smc(struct pp_hwmgr *hwmgr, uint16_t msg, uint32_t *resp)
 	    (resp && !hwmgr->smumgr_funcs->get_argument))
 		return -EINVAL;
 
+	mutex_lock(&hwmgr->msg_lock);
+
 	ret = hwmgr->smumgr_funcs->send_msg_to_smc(hwmgr, msg);
-	if (ret)
+	if (ret) {
+		mutex_unlock(&hwmgr->msg_lock);
 		return ret;
+	}
 
 	if (resp)
 		*resp = hwmgr->smumgr_funcs->get_argument(hwmgr);
 
+	mutex_unlock(&hwmgr->msg_lock);
+
 	return ret;
 }
 
@@ -158,14 +164,20 @@ int smum_send_msg_to_smc_with_parameter(struct pp_hwmgr *hwmgr,
 	    (resp && !hwmgr->smumgr_funcs->get_argument))
 		return -EINVAL;
 
+	mutex_lock(&hwmgr->msg_lock);
+
 	ret = hwmgr->smumgr_funcs->send_msg_to_smc_with_parameter(
 						hwmgr, msg, parameter);
-	if (ret)
+	if (ret) {
+		mutex_unlock(&hwmgr->msg_lock);
 		return ret;
+	}
 
 	if (resp)
 		*resp = hwmgr->smumgr_funcs->get_argument(hwmgr);
 
+	mutex_unlock(&hwmgr->msg_lock);
+
 	return ret;
 }
 
-- 
2.26.0