[1/4] drm/client: Do not pin in drm_client_buffer_vmap()

Commit Message

Thomas Zimmermann April 4, 2025, 1:23 p.m. UTC

Pin and vmap are two distict operations. Do not mix them.

The helper drm_client_buffer_vmap() maps the pages for fbdev-dma
and fbdev-shmem. In both cases, the vmap operation ensures that
the pages are available until the vunmap happens. And as the pages
in DMA or SHMEM areas cannot be moved, there is no reason to call
pin. Hence remove the pin call.

Update drm_client_buffer_vunmap() accordingly.

Signed-off-by: Thomas Zimmermann <[e-mail]>
---
 drivers/gpu/drm/drm_client.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

Patch

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index f1de7faf9fb45..154693066a127 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -303,34 +303,23 @@  EXPORT_SYMBOL(drm_client_buffer_vunmap_local);
  * Returns:
  *	0 on success, or a negative errno code otherwise.
  */
-int
-drm_client_buffer_vmap(struct drm_client_buffer *buffer,
-		       struct iosys_map *map_copy)
+int drm_client_buffer_vmap(struct drm_client_buffer *buffer,
+			   struct iosys_map *map_copy)
 {
 	struct drm_gem_object *gem = buffer->gem;
 	struct iosys_map *map = &buffer->map;
 	int ret;
 
 	drm_gem_lock(gem);
-
-	ret = drm_gem_pin_locked(gem);
-	if (ret)
-		goto err_drm_gem_pin_locked;
 	ret = drm_gem_vmap_locked(gem, map);
-	if (ret)
-		goto err_drm_gem_vmap;
-
 	drm_gem_unlock(gem);
 
+	if (ret)
+		return ret;
+
 	*map_copy = *map;
 
 	return 0;
-
-err_drm_gem_vmap:
-	drm_gem_unpin_locked(buffer->gem);
-err_drm_gem_pin_locked:
-	drm_gem_unlock(gem);
-	return ret;
 }
 EXPORT_SYMBOL(drm_client_buffer_vmap);
 
@@ -349,7 +338,6 @@  void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 
 	drm_gem_lock(gem);
 	drm_gem_vunmap_locked(gem, map);
-	drm_gem_unpin_locked(gem);
 	drm_gem_unlock(gem);
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);