git.ipfire.org Git - thirdparty/kernel/stable-queue.git/blob

   1 From 627530c32a43283474e9dd3e954519410ffa033a Mon Sep 17 00:00:00 2001
   2 From: Frank Schaefer <fschaefer.oss@googlemail.com>
   3 Date: Sat, 9 Aug 2014 06:37:20 -0300
   4 Subject: media: em28xx-v4l: give back all active video buffers to the vb2 core properly on streaming stop
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 From: Frank Schaefer <fschaefer.oss@googlemail.com>
  10
  11 commit 627530c32a43283474e9dd3e954519410ffa033a upstream.
  12
  13 When a new video frame is started, the driver takes the next video buffer from
  14 the list of active buffers and moves it to dev->usb_ctl.vid_buf / dev->usb_ctl.vbi_buf
  15 for further processing.
  16
  17 On streaming stop we currently only give back the pending buffers from the list
  18 but not the ones which are currently processed.
  19
  20 This causes the following warning from the vb2 core since kernel 3.15:
  21
  22 ...
  23  ------------[ cut here ]------------
  24  WARNING: CPU: 1 PID: 2284 at drivers/media/v4l2-core/videobuf2-core.c:2115 __vb2_queue_cancel+0xed/0x150 [videobuf2_core]()
  25  [...]
  26  Call Trace:
  27   [<c0769c46>] dump_stack+0x48/0x69
  28   [<c0245b69>] warn_slowpath_common+0x79/0x90
  29   [<f925e4ad>] ? __vb2_queue_cancel+0xed/0x150 [videobuf2_core]
  30   [<f925e4ad>] ? __vb2_queue_cancel+0xed/0x150 [videobuf2_core]
  31   [<c0245bfd>] warn_slowpath_null+0x1d/0x20
  32   [<f925e4ad>] __vb2_queue_cancel+0xed/0x150 [videobuf2_core]
  33   [<f925fa35>] vb2_internal_streamoff+0x35/0x90 [videobuf2_core]
  34   [<f925fac5>] vb2_streamoff+0x35/0x60 [videobuf2_core]
  35   [<f925fb27>] vb2_ioctl_streamoff+0x37/0x40 [videobuf2_core]
  36   [<f8e45895>] v4l_streamoff+0x15/0x20 [videodev]
  37   [<f8e4925d>] __video_do_ioctl+0x23d/0x2d0 [videodev]
  38   [<f8e49020>] ? video_ioctl2+0x20/0x20 [videodev]
  39   [<f8e48c63>] video_usercopy+0x203/0x5a0 [videodev]
  40   [<f8e49020>] ? video_ioctl2+0x20/0x20 [videodev]
  41   [<c039d0e7>] ? fsnotify+0x1e7/0x2b0
  42   [<f8e49012>] video_ioctl2+0x12/0x20 [videodev]
  43   [<f8e49020>] ? video_ioctl2+0x20/0x20 [videodev]
  44   [<f8e4461e>] v4l2_ioctl+0xee/0x130 [videodev]
  45   [<f8e44530>] ? v4l2_open+0xf0/0xf0 [videodev]
  46   [<c0378de2>] do_vfs_ioctl+0x2e2/0x4d0
  47   [<c0368eec>] ? vfs_write+0x13c/0x1c0
  48   [<c0369a8f>] ? vfs_writev+0x2f/0x50
  49   [<c0379028>] SyS_ioctl+0x58/0x80
  50   [<c076fff3>] sysenter_do_call+0x12/0x12
  51  ---[ end trace 5545f934409f13f4 ]---
  52 ...
  53
  54 Many thanks to Hans Verkuil, whose recently added check in the vb2 core unveiled
  55 this long standing issue and who has investigated it further.
  56
  57 Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
  58 Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
  59 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  60
  61 ---
  62  drivers/media/usb/em28xx/em28xx-video.c |   10 ++++++++--
  63  1 file changed, 8 insertions(+), 2 deletions(-)
  64
  65 --- a/drivers/media/usb/em28xx/em28xx-video.c
  66 +++ b/drivers/media/usb/em28xx/em28xx-video.c
  67 @@ -696,13 +696,16 @@ static int em28xx_stop_streaming(struct
  68         }
  69
  70         spin_lock_irqsave(&dev->slock, flags);
  71 +       if (dev->usb_ctl.vid_buf != NULL) {
  72 +               vb2_buffer_done(&dev->usb_ctl.vid_buf->vb, VB2_BUF_STATE_ERROR);
  73 +               dev->usb_ctl.vid_buf = NULL;
  74 +       }
  75         while (!list_empty(&vidq->active)) {
  76                 struct em28xx_buffer *buf;
  77                 buf = list_entry(vidq->active.next, struct em28xx_buffer, list);
  78                 list_del(&buf->list);
  79                 vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
  80         }
  81 -       dev->usb_ctl.vid_buf = NULL;
  82         spin_unlock_irqrestore(&dev->slock, flags);
  83
  84         return 0;
  85 @@ -724,13 +727,16 @@ int em28xx_stop_vbi_streaming(struct vb2
  86         }
  87
  88         spin_lock_irqsave(&dev->slock, flags);
  89 +       if (dev->usb_ctl.vbi_buf != NULL) {
  90 +               vb2_buffer_done(&dev->usb_ctl.vbi_buf->vb, VB2_BUF_STATE_ERROR);
  91 +               dev->usb_ctl.vbi_buf = NULL;
  92 +       }
  93         while (!list_empty(&vbiq->active)) {
  94                 struct em28xx_buffer *buf;
  95                 buf = list_entry(vbiq->active.next, struct em28xx_buffer, list);
  96                 list_del(&buf->list);
  97                 vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
  98         }
  99 -       dev->usb_ctl.vbi_buf = NULL;
 100         spin_unlock_irqrestore(&dev->slock, flags);
 101
 102         return 0;