drm: modify drm_global_item_ref to avoid two times of writing ref->object
In previous drm_global_item_ref, there are two times of writing
ref->object if item->refcount is 0. So this patch does a minor update
to put alloc and init ref firstly, and then to modify the item of glob
array. Use "else" to avoid two times of writing ref->object. It can
make the code logic more clearly.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/drm_global.c b/drivers/gpu/drm/drm_global.c
index 3d2e91c..b404287 100644
--- a/drivers/gpu/drm/drm_global.c
+++ b/drivers/gpu/drm/drm_global.c
@@ -65,30 +65,34 @@
int drm_global_item_ref(struct drm_global_reference *ref)
{
- int ret;
+ int ret = 0;
struct drm_global_item *item = &glob[ref->global_type];
mutex_lock(&item->mutex);
if (item->refcount == 0) {
- item->object = kzalloc(ref->size, GFP_KERNEL);
- if (unlikely(item->object == NULL)) {
+ ref->object = kzalloc(ref->size, GFP_KERNEL);
+ if (unlikely(ref->object == NULL)) {
ret = -ENOMEM;
- goto out_err;
+ goto error_unlock;
}
-
- ref->object = item->object;
ret = ref->init(ref);
if (unlikely(ret != 0))
- goto out_err;
+ goto error_free;
+ item->object = ref->object;
+ } else {
+ ref->object = item->object;
}
+
++item->refcount;
- ref->object = item->object;
mutex_unlock(&item->mutex);
return 0;
-out_err:
+
+error_free:
+ kfree(ref->object);
+ ref->object = NULL;
+error_unlock:
mutex_unlock(&item->mutex);
- item->object = NULL;
return ret;
}
EXPORT_SYMBOL(drm_global_item_ref);