releases/4.19.31/media-videobuf2-v4l2-drop-warn_on-in-vb2_warn_zero_bytesused.patch

   1 From 5e99456c20f712dcc13d9f6ca4278937d5367355 Mon Sep 17 00:00:00 2001
   2 From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
   3 Date: Mon, 19 Nov 2018 10:33:44 -0500
   4 Subject: media: videobuf2-v4l2: drop WARN_ON in vb2_warn_zero_bytesused()
   5
   6 From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
   7
   8 commit 5e99456c20f712dcc13d9f6ca4278937d5367355 upstream.
   9
  10 Userspace shouldn't set bytesused to 0 for output buffers.
  11 vb2_warn_zero_bytesused() warns about this (only once!), but it also
  12 calls WARN_ON(1), which is confusing since it is not immediately clear
  13 that it warns about a 0 value for bytesused.
  14
  15 Just drop the WARN_ON as it serves no purpose.
  16
  17 Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
  18 Acked-by: Ezequiel Garcia <ezequiel@collabora.com>
  19 Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
  20 Cc: Matthias Maennich <maennich@google.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/media/common/videobuf2/videobuf2-v4l2.c |    1 -
  25  1 file changed, 1 deletion(-)
  26
  27 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
  28 +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
  29 @@ -145,7 +145,6 @@ static void vb2_warn_zero_bytesused(stru
  30                 return;
  31
  32         check_once = true;
  33 -       WARN_ON(1);
  34
  35         pr_warn("use of bytesused == 0 is deprecated and will be removed in the future,\n");
  36         if (vb->vb2_queue->allow_zero_bytesused)