drm/rockchip: fix dma_alloc_attrs() error check

dma_alloc_attrs() returns NULL if it cannot allocate a dma buffer (or
mapping), not a negative error code.

Rerported-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index bc98a227dc76..7ca8799ef784 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -34,12 +34,9 @@ static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj)
         rk_obj->kvaddr = dma_alloc_attrs(drm->dev, obj->size,
                                          &rk_obj->dma_addr, GFP_KERNEL,
                                          &rk_obj->dma_attrs);
-        if (IS_ERR(rk_obj->kvaddr)) {
-                int ret = PTR_ERR(rk_obj->kvaddr);
-
-                DRM_ERROR("failed to allocate %#x byte dma buffer, %d",
-                          obj->size, ret);
-                return ret;
+        if (!rk_obj->kvaddr) {
+                DRM_ERROR("failed to allocate %#x byte dma buffer", obj->size);
+                return -ENOMEM;
         }
 
         return 0;