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 <[email protected]>
Signed-off-by: Rex Zhu <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Rex Zhu

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;

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;