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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-22 03:50:31 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-22 03:50:31 +0300
commit13a3cec8443290b082af2a5254562aca247fe591 (patch)
tree5c873a2c9333be348266234ac5d7101caa1b6d7d /Documentation/video4linux
parent973c9f4f49ca96a53bcf6384c4c59ccd26c33906 (diff)
parent88914bdf8c677ebd7e797adac05e47303fd6ac77 (diff)
downloadlinux-13a3cec8443290b082af2a5254562aca247fe591.tar.xz
Merge branch 'media_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6
* 'media_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (101 commits) [media] staging/lirc: fix mem leaks and ptr err usage [media] hdpvr: reduce latency of i2c read/write w/recycled buffer [media] hdpvr: enable IR part [media] rc/mceusb: timeout should be in ns, not us [media] v4l2-device: fix 'use-after-freed' oops [media] v4l2-dev: don't memset video_device.dev [media] zoran: use video_device_alloc instead of kmalloc [media] w9966: zero device state after a detach [media] v4l: Fix a use-before-set in the control framework [media] v4l: Include linux/videodev2.h in media/v4l2-ctrls.h [media] DocBook/v4l: update V4L2 revision and update copyright years [media] DocBook/v4l: fix validation error in dev-rds.xml [media] v4l2-ctrls: queryctrl shouldn't attempt to replace V4L2_CID_PRIVATE_BASE IDs [media] v4l2-ctrls: fix missing 'read-only' check [media] pvrusb2: Provide more information about IR units to lirc_zilog and ir-kbd-i2c [media] ir-kbd-i2c: Add back defaults setting for Zilog Z8's at addr 0x71 [media] lirc_zilog: Update TODO.lirc_zilog [media] lirc_zilog: Add Andy Walls to copyright notice and authors list [media] lirc_zilog: Remove useless struct i2c_driver.command function [media] lirc_zilog: Remove unneeded tests for existence of the IR Tx function ...
Diffstat (limited to 'Documentation/video4linux')
-rw-r--r--Documentation/video4linux/v4l2-controls.txt12
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 8773778d23fc..881e7f44491b 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -285,6 +285,9 @@ implement g_volatile_ctrl like this:
The 'new value' union is not used in g_volatile_ctrl. In general controls
that need to implement g_volatile_ctrl are read-only controls.
+Note that if one or more controls in a control cluster are marked as volatile,
+then all the controls in the cluster are seen as volatile.
+
To mark a control as volatile you have to set the is_volatile flag:
ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...);
@@ -462,6 +465,15 @@ pointer to the v4l2_ctrl_ops struct that is used for that cluster.
Obviously, all controls in the cluster array must be initialized to either
a valid control or to NULL.
+In rare cases you might want to know which controls of a cluster actually
+were set explicitly by the user. For this you can check the 'is_new' flag of
+each control. For example, in the case of a volume/mute cluster the 'is_new'
+flag of the mute control would be set if the user called VIDIOC_S_CTRL for
+mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume
+controls, then the 'is_new' flag would be 1 for both controls.
+
+The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup().
+
VIDIOC_LOG_STATUS Support
=========================