[PATCH v2 1/3] drm: Make the prime vmap/vunmap hooks optional.

[Eric Anholt <eric@anholt.net>]

Some drivers leave these unimplemented, so don't make them have
unimplemented stubs.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/gpu/drm/drm_prime.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index caf675e3e692..397b46b33739 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -409,7 +409,10 @@ void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 	struct drm_gem_object *obj = dma_buf->priv;
 	struct drm_device *dev = obj->dev;
 
-	return dev->driver->gem_prime_vmap(obj);
+	if (dev->driver->gem_prime_vmap)
+		return dev->driver->gem_prime_vmap(obj);
+	else
+		return NULL;
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
 
@@ -426,7 +429,8 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 	struct drm_gem_object *obj = dma_buf->priv;
 	struct drm_device *dev = obj->dev;
 
-	dev->driver->gem_prime_vunmap(obj, vaddr);
+	if (dev->driver->gem_prime_vunmap)
+		dev->driver->gem_prime_vunmap(obj, vaddr);
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
 
-- 
2.17.0