Commit Graph

3 Commits

Author SHA1 Message Date
Nikolaus Schulz
30ad64b8ac [media] dvb: push down ioctl lock in dvb_usercopy
Since most dvb ioctls wrap their real work with dvb_usercopy, the static mutex
used in dvb_usercopy effectively is a global lock for dvb ioctls.
Unfortunately, frontend ioctls can be blocked by the frontend thread for
several seconds; this leads to unacceptable lock contention.  Mitigate that by
pushing the mutex from dvb_usercopy down to the individual, device specific
ioctls.
There are 10 such ioctl functions using dvb_usercopy, either calling it
directly, or via the trivial wrapper dvb_generic_ioctl. The following already
employ their own locking and look safe:
    • dvb_demux_ioctl           (as per dvb_demux_do_ioctl)
    • dvb_dvr_ioctl             (as per dvb_dvr_do_ioctl)
    • dvb_osd_ioctl             (as per single non-trivial callee)
    • fdtv_ca_ioctl             (as per callees)
    • dvb_frontend_ioctl
The following functions do not, and are thus changed to use a device specific
mutex:
    • dvb_net_ioctl             (as per dvb_net_do_ioctl)
    • dvb_ca_en50221_io_ioctl   (as per dvb_ca_en50221_io_do_ioctl)
    • dvb_video_ioctl
    • dvb_audio_ioctl
    • dvb_ca_ioctl

Signed-off-by: Nikolaus Schulz <schulz@macnetix.de>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-12-27 15:44:21 -02:00
Linus Torvalds
0b8e74c6f4 Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
 "The first part of the media updates for Kernel 3.7.

  This series contain:

   - A major tree renaming patch series: now, drivers are organized
     internally by their used bus, instead of by V4L2 and/or DVB API,
     providing a cleaner driver location for hybrid drivers that
     implement both APIs, and allowing to cleanup the Kconfig items and
     make them more intuitive for the end user;

   - Media Kernel developers are typically very lazy with their duties
     of keeping the MAINTAINERS entries for their drivers updated.  As
     now the tree is more organized, we're doing an effort to add/update
     those entries for the drivers that aren't currently orphan;

   - Several DVB USB drivers got moved to a new DVB USB v2 core; the new
     core fixes several bugs (as the existing one that got bitroted).
     Now, suspend/resume finally started to work fine (at least with
     some devices - we should expect more work with regards to it);

   - added multistream support for DVB-T2, and unified the API for
     DVB-S2 and ISDB-S.  Backward binary support is preserved;

   - as usual, a few new drivers, some V4L2 core improvements and lots
     of drivers improvements and fixes.

  There are some points to notice on this series:

   1) you should expect a trivial merge conflict on your tree, with the
      removal of Documentation/feature-removal-schedule.txt: this series
      would be adding two additional entries there.  I opted to not
      rebase it due to this recent change;

   2) With regards to the PCTV 520e udev-related breakage, I opted to
      fix it in a way that the patches can be backported to 3.5 even
      without your firmware fix patch.  This way, Greg doesn't need to
      rush backporting your patch (as there are still the firmware cache
      and firmware path customization issues to be addressed there).

      I'll send later a patch (likely after the end of the merge window)
      reverting the rest of the DRX-K async firmware request, fully
      restoring its original behaviour to allow media drivers to
      initialize everything serialized as before for 3.7 and upper.

   3) I'm planning to work on this weekend to test the DMABUF patches
      for V4L2.  The patches are on my queue for several Kernel cycles,
      but, up to now, there is/was no way to test the series locally.

      I have some concerns about this particular changeset with regards
      to security issues, and with regards to the replacement of the old
      VIDIOC_OVERLAY ioctl's that is broken on modern systems, due to
      GPU drivers change.  The Overlay API allows direct PCI2PCI
      transfers from a media capture card into the GPU framebuffer, but
      its API is crappy.  Also, the only existing X11 driver that
      implements it requires a XV extension that is not available
      anymore on modern drivers.  The DMABUF can do the same thing, but
      with it is promising to be a properly-designed API.  If I can
      successfully test this series and be happy with it, I should be
      asking you to pull them next week."

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (717 commits)
  em28xx: regression fix: use DRX-K sync firmware requests on em28xx
  drxk: allow loading firmware synchrousnously
  em28xx: Make all em28xx extensions to be initialized asynchronously
  [media] tda18271: properly report read errors in tda18271_get_id
  [media] tda18271: delay IR & RF calibration until init() if delay_cal is set
  [media] MAINTAINERS: add Michael Krufky as tda827x maintainer
  [media] MAINTAINERS: add Michael Krufky as tda8290 maintainer
  [media] MAINTAINERS: add Michael Krufky as cxusb maintainer
  [media] MAINTAINERS: add Michael Krufky as lg2160 maintainer
  [media] MAINTAINERS: add Michael Krufky as lgdt3305 maintainer
  [media] MAINTAINERS: add Michael Krufky as mxl111sf maintainer
  [media] MAINTAINERS: add Michael Krufky as mxl5007t maintainer
  [media] MAINTAINERS: add Michael Krufky as tda18271 maintainer
  [media] s5p-tv: Report only multi-plane capabilities in vidioc_querycap
  [media] s5p-mfc: Fix misplaced return statement in s5p_mfc_suspend()
  [media] exynos-gsc: Add missing static storage class specifiers
  [media] exynos-gsc: Remove <linux/version.h> header file inclusion
  [media] s5p-fimc: Fix incorrect condition in fimc_lite_reqbufs()
  [media] s5p-tv: Fix potential NULL pointer dereference error
  [media] s5k6aa: Fix possible NULL pointer dereference
  ...
2012-10-07 17:49:05 +09:00
Mauro Carvalho Chehab
3d6c2bc08a [media] dvb: move the dvb core one level up
just like the V4L2 core, move the DVB core to drivers/media, as the
intention is to get rid of both "video" and "dvb" directories.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-08-13 23:08:14 -03:00