[PATCH 5.1 73/96] drm/amd/powerplay: use hardware fan control if no powerplay fan table

[Greg Kroah-Hartman]

From: Evan Quan <evan.q...@amd.com>

commit f78c581e22d4b33359ac3462e8d0504735df01f4 upstream.

Otherwise, you may get divided-by-zero error or corrput the SMU fan
control feature.

Signed-off-by: Evan Quan <evan.q...@amd.com>
Reviewed-by: Alex Deucher <alexander.deuc...@amd.com>
Tested-by: Slava Abramov <slava.abra...@amd.com>
Acked-by: Slava Abramov <slava.abra...@amd.com>
Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
Cc: sta...@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/gpu/drm/amd/powerplay/hwmgr/process_pptables_v1_0.c |    4 +++-
 drivers/gpu/drm/amd/powerplay/inc/hwmgr.h                   |    1 +
 drivers/gpu/drm/amd/powerplay/smumgr/polaris10_smumgr.c     |    4 ++++
 3 files changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/powerplay/hwmgr/process_pptables_v1_0.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/process_pptables_v1_0.c
@@ -916,8 +916,10 @@ static int init_thermal_controller(
                        PHM_PlatformCaps_ThermalController
                  );
 
-       if (0 == powerplay_table->usFanTableOffset)
+       if (0 == powerplay_table->usFanTableOffset) {
+               hwmgr->thermal_controller.use_hw_fan_control = 1;
                return 0;
+       }
 
        fan_table = (const PPTable_Generic_SubTable_Header *)
                (((unsigned long)powerplay_table) +
--- a/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h
+++ b/drivers/gpu/drm/amd/powerplay/inc/hwmgr.h
@@ -694,6 +694,7 @@ struct pp_thermal_controller_info {
        uint8_t ucType;
        uint8_t ucI2cLine;
        uint8_t ucI2cAddress;
+       uint8_t use_hw_fan_control;
        struct pp_fan_info fanInfo;
        struct pp_advance_fan_control_parameters advanceFanControlParameters;
 };
--- a/drivers/gpu/drm/amd/powerplay/smumgr/polaris10_smumgr.c
+++ b/drivers/gpu/drm/amd/powerplay/smumgr/polaris10_smumgr.c
@@ -2092,6 +2092,10 @@ static int polaris10_thermal_setup_fan_t
                return 0;
        }
 
+       /* use hardware fan control */
+       if (hwmgr->thermal_controller.use_hw_fan_control)
+               return 0;
+
        tmp64 = hwmgr->thermal_controller.advanceFanControlParameters.
                        usPWMMin * duty100;
        do_div(tmp64, 10000);