From: Rex Zhu <Rex.Zhu@amd.com>
Date: Thu, 20 Sep 2018 03:50:26 +0000 (+0800)
Subject: drm/amd/pp: Avoid divide-by-zero in fan_ctrl_set_fan_speed_rpm
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=c52dcf49195d06319189c7f1dd8b62bfca545197;p=openwrt%2Fstaging%2Fblogic.git

drm/amd/pp: Avoid divide-by-zero in fan_ctrl_set_fan_speed_rpm

The minRPM speed maybe equal to zero. so need to check
input RPM not equal to 0, otherwise cause divide-by-zero driver crash.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---

diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_thermal.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_thermal.c
index eef086c5afb6..5bdc0df5a9f4 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_thermal.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_thermal.c
@@ -260,6 +260,7 @@ int smu7_fan_ctrl_set_fan_speed_rpm(struct pp_hwmgr *hwmgr, uint32_t speed)
 	if (hwmgr->thermal_controller.fanInfo.bNoFan ||
 			(hwmgr->thermal_controller.fanInfo.
 			ucTachometerPulsesPerRevolution == 0) ||
+			speed == 0 ||
 			(speed < hwmgr->thermal_controller.fanInfo.ulMinRPM) ||
 			(speed > hwmgr->thermal_controller.fanInfo.ulMaxRPM))
 		return 0;
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_thermal.c b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_thermal.c
index 538de6cfa23f..3f807d6c95ce 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_thermal.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/vega10_thermal.c
@@ -312,6 +312,7 @@ int vega10_fan_ctrl_set_fan_speed_rpm(struct pp_hwmgr *hwmgr, uint32_t speed)
 	int result = 0;
 
 	if (hwmgr->thermal_controller.fanInfo.bNoFan ||
+	    speed == 0 ||
 	    (speed < hwmgr->thermal_controller.fanInfo.ulMinRPM) ||
 	    (speed > hwmgr->thermal_controller.fanInfo.ulMaxRPM))
 		return -1;