drm/prime: fix sgt NULL checking

The drm_gem_map_detach() can be called with sgt is NULL.

Change-Id: I2a422a1bf92333e60de902ab048048f0b4c754dc
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 1e0de41..ff5fece 100644 (file)
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -119,12 +119,13 @@ static void drm_gem_map_detach(struct dma_buf *dma_buf,
                return;
 
        sgt = prime_attach->sgt;
+       if (sgt) {
+               if (prime_attach->dir != DMA_NONE)
+                       dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
+                                       prime_attach->dir);
+               sg_free_table(sgt);
+       }
 
-       if (prime_attach->dir != DMA_NONE)
-               dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
-                               prime_attach->dir);
-
-       sg_free_table(sgt);
        kfree(sgt);
        kfree(prime_attach);
        attach->priv = NULL;