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  1. 06 10月, 2012 1 次提交
  3. 02 10月, 2012 1 次提交
  5. 26 9月, 2012 1 次提交
  7. 14 9月, 2012 2 次提交
  9. 14 8月, 2012 1 次提交
  11. 31 7月, 2012 2 次提交
  13. 15 5月, 2012 12 次提交
  15. 14 5月, 2012 3 次提交
  17. 08 5月, 2012 2 次提交
  19. 20 4月, 2012 1 次提交
  21. 18 4月, 2012 2 次提交
  23. 11 4月, 2012 1 次提交
  25. 20 3月, 2012 1 次提交
  27. 08 3月, 2012 1 次提交
    • H
      [media] v4l2-ctrls: v4l2_ctrl_add_handler should add all refs · 072e6602
      由 Hans Verkuil 提交于 
      Currently v4l2_ctrl_add_handler adds only the controls that are owned
by the handler. This is wrong. Instead all controls, whether owned or
not, should be added.

This is also implied by the v4l2-controls.txt documentation and it is
clearly the right thing to do. The only reason this was never noticed
before is because we never did this. Only recent changes in ivtv made
this error visible because there a third handler layer was added (handler
A inherits from handler B which inherits from C, D and E). Without this
change handler A only sees the controls owned by handler B and the controls
from C, D and E are missing.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      072e6602
  29. 29 2月, 2012 1 次提交
    • S
      [media] V4L: Add JPEG compression control class · c7361ae1
      由 Sylwester Nawrocki 提交于 
      The V4L2_CID_JPEG_CLASS control class is intended to expose various
adjustable parameters of JPEG encoders and decoders. Following controls
are defined:

 - V4L2_CID_JPEG_CHROMA_SUBSAMPLING,
 - V4L2_CID_JPEG_RESTART_INTERVAL,
 - V4L2_CID_JPEG_COMPRESSION_QUALITY,
 - V4L2_CID_JPEG_ACTIVE_MARKER.

This covers only a part of relevant standard specifications. More
controls should be added in future if required.

The purpose of V4L2_CID_JPEG_CLASS class is also to replace some
functionality covered by VIDIOC_S/G_JPEGCOMP ioctls, i.e. the JPEG
markers presence and compression quality control. The applications
and drivers should switch from the ioctl to control based API, as
described in the subsequent patches for the Media API DocBook.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      c7361ae1
  31. 15 2月, 2012 2 次提交
  33. 14 2月, 2012 1 次提交
  35. 18 1月, 2012 1 次提交
  37. 31 12月, 2011 2 次提交
  39. 08 11月, 2011 2 次提交
    • H
      [media] v4l2-ctrl: Send change events to all fh for auto cluster slave controls · 1249a3a8
      由 Hans de Goede 提交于 
      Otherwise the fh changing the master control won't get the inactive state
change event for the slave controls.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      1249a3a8
    • H
      [media] v4l2-event: Don't set sev->fh to NULL on unsubscribe · e3e72f39
      由 Hans de Goede 提交于 
      Setting sev->fh to NULL causes problems for the del op added in the next
patch of this series, since this op needs a way to get to its own data
structures, and typically this will be done by using container_of on an
embedded v4l2_fh struct.

The reason the original code is setting sev->fh to NULL is to signal
to users of the event framework that the unsubscription has happened,
but since their is no shared lock between the event framework and users
of it, this is inherently racy, and it also turns out to be unnecessary
as long as both the event framework and the user of the framework do their
own locking properly and the user guarantees that it holds no references
to the subcribed_event structure after its del operation has been called.

This is best explained by looking at the only code currently checking for
sev->fh being set to NULL on unsubscribe, which is the v4l2-ctrls.c send_event
function. Here is the relevant code from v4l2-ctrls: send_event():

	if (sev->fh && (sev->fh != fh ||
			(sev->flags & V4L2_EVENT_SUB_FL_ALLOW_FEEDBACK)))
		v4l2_event_queue_fh(sev->fh, &ev);

Now lets say that v4l2_event_unsubscribe and v4l2-ctrls: send_event() race
on the same sev, then the following could happens:

1) send_event checks sev->fh, finds it is not NULL
<thread switch>
2) v4l2_event_unsubscribe sets sev->fh NULL
3) v4l2_event_unsubscribe calls v4l2_ctrls del_event function, this blocks
   as the thread calling send_event holds the ctrl_lock
<thread switch>
4) send_event calls v4l2_event_queue_fh(sev->fh, &ev) which not is equivalent
   to calling: v4l2_event_queue_fh(NULL, &ev)
5) oops, NULL pointer deref.

Now again without setting sev->fh to NULL in v4l2_event_unsubscribe and
without the (now senseless since always true) sev->fh != NULL check in

1) send_event is about to call v4l2_event_queue_fh(sev->fh, &ev)
<thread switch>
2) v4l2_event_unsubscribe removes sev->list from the fh->subscribed list
<thread switch>
3) send_event calls v4l2_event_queue_fh(sev->fh, &ev)
4) v4l2_event_queue_fh blocks on the fh_lock spinlock
<thread switch>
5) v4l2_event_unsubscribe unlocks the fh_lock spinlock
6) v4l2_event_unsubscribe calls v4l2_ctrls del_event function, this blocks
   as the thread calling send_event holds the ctrl_lock
<thread switch>
8) v4l2_event_queue_fh takes the fh_lock
7) v4l2_event_queue_fh calls v4l2_event_subscribed, does not find it since
   sev->list has been removed from fh->subscribed already -> does nothing
9) v4l2_event_queue_fh releases the fh_lock
10) the caller of send_event releases the ctrl lock (mutex)
<thread switch>
11) v4l2_ctrls del_event takes the ctrl lock
12) v4l2_ctrls del_event removes sev->node from the ev_subs list
13) v4l2_ctrls del_event releases the ctrl lock
14) v4l2_event_unsubscribe frees the sev, to which no references are being
    held anymore
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Acked-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>
      e3e72f39