Am 08.09.2016 um 04:07 schrieb Huang Rui: > 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. > > Signed-off-by: Huang Rui <ray.huang at amd.com>
Reviewed-by: Christian König <christian.koenig at amd.com>. > --- > > Changes from V2 -> V3: > - Use duplicate mutex release to avoid "goto" in non-error patch. > - Rename error label > > --- > drivers/gpu/drm/drm_global.c | 24 ++++++++++++++---------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > 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 @@ void drm_global_release(void) > > 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);