drm/nouveau/hwmon: do not expose a buggy temperature if it is unavailable

Signed-off-by: Martin Peres <martin.peres@labri.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 31 insertions, 13 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_pm.c b/drivers/gpu/drm/nouveau/nouveau_pm.c
index bb54098c6d97..936b442a6ab7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_pm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_pm.c
@@ -402,8 +402,12 @@ nouveau_hwmon_show_temp(struct device *d, struct device_attribute *a, char *buf)
         struct drm_device *dev = dev_get_drvdata(d);
         struct nouveau_drm *drm = nouveau_drm(dev);
         struct nouveau_therm *therm = nouveau_therm(drm->device);
+        int temp = therm->temp_get(therm);
 
-        return snprintf(buf, PAGE_SIZE, "%d\n", therm->temp_get(therm) * 1000);
+        if (temp < 0)
+                return temp;
+
+        return snprintf(buf, PAGE_SIZE, "%d\n", temp * 1000);
 }
 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, nouveau_hwmon_show_temp,
                                                   NULL, 0);
@@ -871,7 +875,12 @@ static SENSOR_DEVICE_ATTR(pwm1_max, S_IRUGO | S_IWUSR,
                           nouveau_hwmon_get_pwm1_max,
                           nouveau_hwmon_set_pwm1_max, 0);
 
-static struct attribute *hwmon_attributes[] = {
+static struct attribute *hwmon_default_attributes[] = {
+        &sensor_dev_attr_name.dev_attr.attr,
+        &sensor_dev_attr_update_rate.dev_attr.attr,
+        NULL
+};
+static struct attribute *hwmon_temp_attributes[] = {
         &sensor_dev_attr_temp1_input.dev_attr.attr,
         &sensor_dev_attr_temp1_auto_point1_pwm.dev_attr.attr,
         &sensor_dev_attr_temp1_auto_point1_temp.dev_attr.attr,
@@ -882,8 +891,6 @@ static struct attribute *hwmon_attributes[] = {
         &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
         &sensor_dev_attr_temp1_emergency.dev_attr.attr,
         &sensor_dev_attr_temp1_emergency_hyst.dev_attr.attr,
-        &sensor_dev_attr_name.dev_attr.attr,
-        &sensor_dev_attr_update_rate.dev_attr.attr,
         NULL
 };
 static struct attribute *hwmon_fan_rpm_attributes[] = {
@@ -898,8 +905,11 @@ static struct attribute *hwmon_pwm_fan_attributes[] = {
         NULL
 };
 
-static const struct attribute_group hwmon_attrgroup = {
-        .attrs = hwmon_attributes,
+static const struct attribute_group hwmon_default_attrgroup = {
+        .attrs = hwmon_default_attributes,
+};
+static const struct attribute_group hwmon_temp_attrgroup = {
+        .attrs = hwmon_temp_attributes,
 };
 static const struct attribute_group hwmon_fan_rpm_attrgroup = {
         .attrs = hwmon_fan_rpm_attributes,
@@ -931,13 +941,22 @@ nouveau_hwmon_init(struct drm_device *dev)
         }
         dev_set_drvdata(hwmon_dev, dev);
 
-        /* default sysfs entries */
-        ret = sysfs_create_group(&hwmon_dev->kobj, &hwmon_attrgroup);
+        /* set the default attributes */
+        ret = sysfs_create_group(&hwmon_dev->kobj, &hwmon_default_attrgroup);
         if (ret) {
                 if (ret)
                         goto error;
         }
 
+        /* if the card has a working thermal sensor */
+        if (therm->temp_get(therm) >= 0) {
+                ret = sysfs_create_group(&hwmon_dev->kobj, &hwmon_temp_attrgroup);
+                if (ret) {
+                        if (ret)
+                                goto error;
+                }
+        }
+
         /* if the card has a pwm fan */
         /*XXX: incorrect, need better detection for this, some boards have
          *     the gpio entries for pwm fan control even when there's no
@@ -979,11 +998,10 @@ nouveau_hwmon_fini(struct drm_device *dev)
         struct nouveau_pm *pm = nouveau_pm(dev);
 
         if (pm->hwmon) {
-                sysfs_remove_group(&pm->hwmon->kobj, &hwmon_attrgroup);
-                sysfs_remove_group(&pm->hwmon->kobj,
-                                   &hwmon_pwm_fan_attrgroup);
-                sysfs_remove_group(&pm->hwmon->kobj,
-                                   &hwmon_fan_rpm_attrgroup);
+                sysfs_remove_group(&pm->hwmon->kobj, &hwmon_default_attrgroup);
+                sysfs_remove_group(&pm->hwmon->kobj, &hwmon_temp_attrgroup);
+                sysfs_remove_group(&pm->hwmon->kobj, &hwmon_pwm_fan_attrgroup);
+                sysfs_remove_group(&pm->hwmon->kobj, &hwmon_fan_rpm_attrgroup);
 
                 hwmon_device_unregister(pm->hwmon);
         }