FOLL_FORCE is really only for ptrace access. According to commit
707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always
writable"), get_vaddr_frames() currently pins all pages writable as a
workaround for issues with read-only buffers.

FOLL_FORCE, however, seems to be a legacy leftover as it predates
commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are
always writable"). Let's just remove it.

Once the read-only buffer issue has been resolved, FOLL_WRITE could
again be set depending on the DMA direction.

Cc: Hans Verkuil <hverk...@xs4all.nl>
Cc: Marek Szyprowski <m.szyprow...@samsung.com>
Cc: Tomasz Figa <tf...@chromium.org>
Cc: Marek Szyprowski <m.szyprow...@samsung.com>
Cc: Mauro Carvalho Chehab <mche...@kernel.org>
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
 drivers/media/common/videobuf2/frame_vector.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/common/videobuf2/frame_vector.c 
b/drivers/media/common/videobuf2/frame_vector.c
index 542dde9d2609..062e98148c53 100644
--- a/drivers/media/common/videobuf2/frame_vector.c
+++ b/drivers/media/common/videobuf2/frame_vector.c
@@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int 
nr_frames,
        start = untagged_addr(start);
 
        ret = pin_user_pages_fast(start, nr_frames,
-                                 FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
+                                 FOLL_WRITE | FOLL_LONGTERM,
                                  (struct page **)(vec->ptrs));
        if (ret > 0) {
                vec->got_ref = true;
-- 
2.38.1

Reply via email to