[PATCH 1/3] drm/amdgpu: Add smu lock around in pp_smu_i2c_bus_access

[Chen, Guchun]

Reviewed-by: Guchun Chen <guchun.chen at amd.com>
Tested-by: Guchun Chen <guchun.chen at amd.com>

Regards,
Guchun

-----Original Message-----
From: Andrey Grodzovsky <andrey.grodzovsky at amd.com> 
Sent: Thursday, September 5, 2019 10:50 AM
To: amd-gfx at lists.freedesktop.org
Cc: alexdeucher at gmail.com; Zhang, Hawking <Hawking.Zhang at amd.com>; Zhou1, Tao <Tao.Zhou1 at amd.com>; Chen, Guchun <Guchun.Chen at amd.com>; Saceleanu, Cristian <Cristian.Saceleanu at amd.com>; Grodzovsky, Andrey <Andrey.Grodzovsky at amd.com>
Subject: [PATCH 1/3] drm/amdgpu: Add smu lock around in pp_smu_i2c_bus_access

Protect from concurrent SMU accesses.

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
---
 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 fa636cb..fa8ad7d 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 = {
--
2.7.4