[PATCH v3 2/3] drm/amd: Make SW CTF handler cope with different read_sensor() results

[Mario Limonciello]

The SW CTF handler assumes that the read_sensor() call always succeeds
and has updated `hotspot_tmp`, but this may not be guaranteed.

For example some of the read_sensor() callbacks will return 0 when a RAS
interrupt is triggered in which case `hotspot_tmp` won't be updated.

Adjust the logic to catch this circumstance and output a warning.

Signed-off-by: Mario Limonciello <mario.limoncie...@amd.com>
---
v2->v3:
 * Correctly handle fallthrough case
v1->v2:
 * Only show `Failed to read hotspot temperature` when sensor read fails
---
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c | 24 ++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c 
b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
index d24fccf28f6a..963cf6e76935 100644
--- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
@@ -1165,21 +1165,27 @@ static void smu_swctf_delayed_work_handler(struct 
work_struct *work)
        struct smu_temperature_range *range =
                                &smu->thermal_range;
        struct amdgpu_device *adev = smu->adev;
-       uint32_t hotspot_tmp, size;
+       uint32_t hotspot_tmp = 0, size;
 
        /*
         * If the hotspot temperature is confirmed as below SW CTF setting point
         * after the delay enforced, nothing will be done.
         * Otherwise, a graceful shutdown will be performed to prevent further 
damage.
         */
-       if (range->software_shutdown_temp &&
-           smu->ppt_funcs->read_sensor &&
-           !smu->ppt_funcs->read_sensor(smu,
-                                        AMDGPU_PP_SENSOR_HOTSPOT_TEMP,
-                                        &hotspot_tmp,
-                                        &size) &&
-           hotspot_tmp / 1000 < range->software_shutdown_temp)
-               return;
+       if (range->software_shutdown_temp && smu->ppt_funcs->read_sensor) {
+               int r = smu->ppt_funcs->read_sensor(smu,
+                                                   
AMDGPU_PP_SENSOR_HOTSPOT_TEMP,
+                                                   &hotspot_tmp,
+                                                   &size);
+               switch (r) {
+               case 0:
+                       if (hotspot_tmp / 1000 < range->software_shutdown_temp)
+                               return;
+                       break;
+               default:
+                       dev_err(adev->dev, "Failed to read hotspot temperature: 
%d\n", r);
+               }
+       }
 
        dev_emerg(adev->dev, "ERROR: GPU over temperature range(SW CTF) 
detected!\n");
        dev_emerg(adev->dev, "ERROR: System is going to shutdown due to GPU SW 
CTF!\n");
-- 
2.34.1