From 1963b7c3beda608501deaf9010b53ec6cb6adbf1 Mon Sep 17 00:00:00 2001
From: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Date: Tue, 3 Sep 2019 16:47:40 -0400
Subject: drm/amdgpu: Add smu lock around in pp_smu_i2c_bus_access
Git-commit: 1963b7c3beda608501deaf9010b53ec6cb6adbf1
Patch-mainline: v5.4-rc1
References: bsc#1152489

Protect from concurrent SMU accesses.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Tao Zhou <tao.zhou1@amd.com>
Reviewed-and-tested-by: Guchun Chen <guchun.chen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/amd/powerplay/amd_powerplay.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
index fa636cb462c1..fa8ad7db2b3a 100644
--- a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
+++ b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
@@ -1531,6 +1531,7 @@ static int pp_asic_reset_mode_2(void *handle)
 static int pp_smu_i2c_bus_access(void *handle, bool acquire)
 {
 	struct pp_hwmgr *hwmgr = handle;
+	int ret = 0;
 
 	if (!hwmgr || !hwmgr->pm_en)
 		return -EINVAL;
@@ -1540,7 +1541,11 @@ static int pp_smu_i2c_bus_access(void *handle, bool acquire)
 		return -EINVAL;
 	}
 
-	return hwmgr->hwmgr_func->smu_i2c_bus_access(hwmgr, acquire);
+	mutex_lock(&hwmgr->smu_lock);
+	ret = hwmgr->hwmgr_func->smu_i2c_bus_access(hwmgr, acquire);
+	mutex_unlock(&hwmgr->smu_lock);
+
+	return ret;
 }
 
 static const struct amd_pm_funcs pp_dpm_funcs = {
-- 
2.28.0