drm/xe/hwmon: Stop ignoring errors on probe

Not registering hwmon because it's not available (SRIOV_VF and DGFX) is
different from failing the initialization. Handle the errors
appropriately.

Cc: Badal Nilawar <badal.nilawar@intel.com>
Cc: Karthik Poosa <karthik.poosa@intel.com>
Reviewed-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250213192909.996148-13-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Author: lucasdemarchi

drivers/gpu/drm/xe/xe_device.c

@@ -895,7 +895,9 @@ int xe_device_probe(struct xe_device *xe)
 
 	xe_debugfs_register(xe);
 
-	xe_hwmon_register(xe);
+	err = xe_hwmon_register(xe);
+	if (err)
+		goto err_unregister_display;
 
 	for_each_gt(gt, xe, id)
 		xe_gt_sanitize_freq(gt);

drivers/gpu/drm/xe/xe_hwmon.c

@@ -839,10 +839,9 @@ static const struct hwmon_chip_info hwmon_chip_info = {
 };
 
 static void
-xe_hwmon_get_preregistration_info(struct xe_device *xe)
+xe_hwmon_get_preregistration_info(struct xe_hwmon *hwmon)
 {
-	struct xe_mmio *mmio = xe_root_tile_mmio(xe);
-	struct xe_hwmon *hwmon = xe->hwmon;
+	struct xe_mmio *mmio = xe_root_tile_mmio(hwmon->xe);
 	long energy;
 	u64 val_sku_unit = 0;
 	int channel;
@@ -876,45 +875,47 @@ static void xe_hwmon_mutex_destroy(void *arg)
 	mutex_destroy(&hwmon->hwmon_lock);
 }
 
-void xe_hwmon_register(struct xe_device *xe)
+int xe_hwmon_register(struct xe_device *xe)
 {
 	struct device *dev = xe->drm.dev;
 	struct xe_hwmon *hwmon;
+	int ret;
 
 	/* hwmon is available only for dGfx */
 	if (!IS_DGFX(xe))
-		return;
+		return 0;
 
 	/* hwmon is not available on VFs */
 	if (IS_SRIOV_VF(xe))
-		return;
+		return 0;
 
 	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
 	if (!hwmon)
-		return;
-
-	xe->hwmon = hwmon;
+		return -ENOMEM;
 
 	mutex_init(&hwmon->hwmon_lock);
-	if (devm_add_action_or_reset(dev, xe_hwmon_mutex_destroy, hwmon))
-		return;
+	ret = devm_add_action_or_reset(dev, xe_hwmon_mutex_destroy, hwmon);
+	if (ret)
+		return ret;
 
 	/* There's only one instance of hwmon per device */
 	hwmon->xe = xe;
+	xe->hwmon = hwmon;
 
-	xe_hwmon_get_preregistration_info(xe);
+	xe_hwmon_get_preregistration_info(hwmon);
 
 	drm_dbg(&xe->drm, "Register xe hwmon interface\n");
 
 	/*  hwmon_dev points to device hwmon<i> */
 	hwmon->hwmon_dev = devm_hwmon_device_register_with_info(dev, "xe", hwmon,
 								&hwmon_chip_info,
 								hwmon_groups);
-
 	if (IS_ERR(hwmon->hwmon_dev)) {
-		drm_warn(&xe->drm, "Failed to register xe hwmon (%pe)\n", hwmon->hwmon_dev);
+		drm_err(&xe->drm, "Failed to register xe hwmon (%pe)\n", hwmon->hwmon_dev);
 		xe->hwmon = NULL;
-		return;
+		return PTR_ERR(hwmon->hwmon_dev);
 	}
+
+	return 0;
 }
 

drivers/gpu/drm/xe/xe_hwmon.h

@@ -11,9 +11,9 @@
 struct xe_device;
 
 #if IS_REACHABLE(CONFIG_HWMON)
-void xe_hwmon_register(struct xe_device *xe);
+int xe_hwmon_register(struct xe_device *xe);
 #else
-static inline void xe_hwmon_register(struct xe_device *xe) { };
+static inline int xe_hwmon_register(struct xe_device *xe) { return 0; };
 #endif
 
 #endif /* _XE_HWMON_H_ */