drm/shmem-helpers: vunmap: Don't put pages for dma-buf

BugLink: https://bugs.launchpad.net/bugs/1919492
commit 64e194e278673bceb68fb2dde7dbc3d812bfceb3 upstream.

dma-buf importing was reworked in commit 7d2cd72a9aa3
("drm/shmem-helpers: Simplify dma-buf importing"). Before that commit
drm_gem_shmem_prime_import_sg_table() did set ->pages_use_count=1 and
drm_gem_shmem_vunmap_locked() could call drm_gem_shmem_put_pages()
unconditionally. Now without the use count set, put pages is called also
on dma-bufs. Fix this by only putting pages if it's not imported.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Fixes: 7d2cd72a9aa3 ("drm/shmem-helpers: Simplify dma-buf importing")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219122203.51130-1-noralf@tronnes.org
(cherry picked from commit cdea72518a2b38207146e92e1c9e2fac15975679)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 5b5c095e86a94081c0a92275a4128c637dd1a34f..6d625cee7a6af2d1b908f0d28708b06d8625a7d5 100644 (file)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -357,13 +357,14 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
        if (--shmem->vmap_use_count > 0)
                return;
 
-       if (obj->import_attach)
+       if (obj->import_attach) {
                dma_buf_vunmap(obj->import_attach->dmabuf, map);
-       else
+       } else {
                vunmap(shmem->vaddr);
+               drm_gem_shmem_put_pages(shmem);
+       }
 
        shmem->vaddr = NULL;
-       drm_gem_shmem_put_pages(shmem);
 }
 
 /*