drm: Unify and fix idr error handling

The error handling code w.r.t. idr usage looks inconsistent.

In the case of drm_mode_object_get() and drm_ctxbitmap_next() the error
handling is also incomplete.

Unify the code to follow the same pattern always.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_context.c

@@ -85,11 +85,12 @@ static int drm_ctxbitmap_next(struct drm_device * dev)
 	mutex_lock(&dev->struct_mutex);
 	ret = idr_get_new_above(&dev->ctx_idr, NULL,
 				DRM_RESERVED_CONTEXTS, &new_id);
-	if (ret == -EAGAIN) {
 	mutex_unlock(&dev->struct_mutex);
+	if (ret == -EAGAIN)
 		goto again;
-	}
-	mutex_unlock(&dev->struct_mutex);
+	else if (ret)
+		return ret;
+
 	return new_id;
 }
 

drivers/gpu/drm/drm_crtc.c

@@ -227,7 +227,7 @@ static int drm_mode_object_get(struct drm_device *dev,
 again:
 	if (idr_pre_get(&dev->mode_config.crtc_idr, GFP_KERNEL) == 0) {
 		DRM_ERROR("Ran out memory getting a mode number\n");
-		return -EINVAL;
+		return -ENOMEM;
 	}
 
 	mutex_lock(&dev->mode_config.idr_mutex);
@@ -235,6 +235,8 @@ static int drm_mode_object_get(struct drm_device *dev,
 	mutex_unlock(&dev->mode_config.idr_mutex);
 	if (ret == -EAGAIN)
 		goto again;
+	else if (ret)
+		return ret;
 
 	obj->id = new_id;
 	obj->type = obj_type;

drivers/gpu/drm/drm_gem.c

@@ -272,8 +272,7 @@ drm_gem_handle_create(struct drm_file *file_priv,
 	spin_unlock(&file_priv->table_lock);
 	if (ret == -EAGAIN)
 		goto again;
-
-	if (ret != 0)
+	else if (ret)
 		return ret;
 
 	drm_gem_object_handle_reference(obj);
@@ -456,8 +455,7 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 
 		if (ret == -EAGAIN)
 			goto again;
-
-		if (ret != 0)
+		else if (ret)
 			goto err;
 
 		/* Allocate a reference for the name table.  */

drivers/gpu/drm/drm_stub.c

@@ -122,11 +122,10 @@ static int drm_minor_get_id(struct drm_device *dev, int type)
 	ret = idr_get_new_above(&drm_minors_idr, NULL,
 				base, &new_id);
 	mutex_unlock(&dev->struct_mutex);
-	if (ret == -EAGAIN) {
+	if (ret == -EAGAIN)
 		goto again;
-	} else if (ret) {
+	else if (ret)
 		return ret;
-	}
 
 	if (new_id >= limit) {
 		idr_remove(&drm_minors_idr, new_id);