drm/vc4: debugfs: Return an error on failure

vc4_debugfs_add_file() can fail, so let's propagate its error code instead
of silencing it.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220711173939.1132294-64-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_debugfs.c

@@ -67,10 +67,10 @@ static int vc4_debugfs_regset32(struct seq_file *m, void *unused)
  * track the request and delay it to be called on each minor during
  * vc4_debugfs_init().
  */
-void vc4_debugfs_add_file(struct drm_device *dev,
-			  const char *name,
-			  int (*show)(struct seq_file*, void*),
-			  void *data)
+int vc4_debugfs_add_file(struct drm_device *dev,
+			 const char *name,
+			 int (*show)(struct seq_file*, void*),
+			 void *data)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 
@@ -78,18 +78,20 @@ void vc4_debugfs_add_file(struct drm_device *dev,
 		devm_kzalloc(dev->dev, sizeof(*entry), GFP_KERNEL);
 
 	if (!entry)
-		return;
+		return -ENOMEM;
 
 	entry->info.name = name;
 	entry->info.show = show;
 	entry->info.data = data;
 
 	list_add(&entry->link, &vc4->debugfs_list);
+
+	return 0;
 }
 
-void vc4_debugfs_add_regset32(struct drm_device *drm,
-			      const char *name,
-			      struct debugfs_regset32 *regset)
+int vc4_debugfs_add_regset32(struct drm_device *drm,
+			     const char *name,
+			     struct debugfs_regset32 *regset)
 {
-	vc4_debugfs_add_file(drm, name, vc4_debugfs_regset32, regset);
+	return vc4_debugfs_add_file(drm, name, vc4_debugfs_regset32, regset);
 }

drivers/gpu/drm/vc4/vc4_drv.h

@@ -866,25 +866,27 @@ void vc4_crtc_get_margins(struct drm_crtc_state *state,
 /* vc4_debugfs.c */
 void vc4_debugfs_init(struct drm_minor *minor);
 #ifdef CONFIG_DEBUG_FS
-void vc4_debugfs_add_file(struct drm_device *drm,
-			  const char *filename,
-			  int (*show)(struct seq_file*, void*),
-			  void *data);
-void vc4_debugfs_add_regset32(struct drm_device *drm,
-			      const char *filename,
-			      struct debugfs_regset32 *regset);
+int vc4_debugfs_add_file(struct drm_device *drm,
+			 const char *filename,
+			 int (*show)(struct seq_file*, void*),
+			 void *data);
+int vc4_debugfs_add_regset32(struct drm_device *drm,
+			     const char *filename,
+			     struct debugfs_regset32 *regset);
 #else
-static inline void vc4_debugfs_add_file(struct drm_device *drm,
-					const char *filename,
-					int (*show)(struct seq_file*, void*),
-					void *data)
+static inline int vc4_debugfs_add_file(struct drm_device *drm,
+				       const char *filename,
+				       int (*show)(struct seq_file*, void*),
+				       void *data)
 {
+	return 0;
 }
 
-static inline void vc4_debugfs_add_regset32(struct drm_device *drm,
-					    const char *filename,
-					    struct debugfs_regset32 *regset)
+static inline int vc4_debugfs_add_regset32(struct drm_device *drm,
+					   const char *filename,
+					   struct debugfs_regset32 *regset)
 {
+	return 0;
 }
 #endif