diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml index 5122ce87e0b8..b17a7aac6997 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml @@ -183,7 +183,12 @@ applications must set the array to zero.</entry> <entry>__u32</entry> <entry><structfield>ctrl_class</structfield></entry> <entry>The control class to which all controls belong, see -<xref linkend="ctrl-class" />.</entry> +<xref linkend="ctrl-class" />. Drivers that use a kernel framework for handling +controls will also accept a value of 0 here, meaning that the controls can +belong to any control class. Whether drivers support this can be tested by setting +<structfield>ctrl_class</structfield> to 0 and calling <constant>VIDIOC_TRY_EXT_CTRLS</constant> +with a <structfield>count</structfield> of 0. If that succeeds, then the driver +supports this feature.</entry> </row> <row> <entry>__u32</entry> @@ -194,10 +199,13 @@ also be zero.</entry> <row> <entry>__u32</entry> <entry><structfield>error_idx</structfield></entry> - <entry>Set by the driver in case of an error. It is the -index of the control causing the error or equal to 'count' when the -error is not associated with a particular control. Undefined when the -ioctl returns 0 (success).</entry> + <entry>Set by the driver in case of an error. If it is equal +to <structfield>count</structfield>, then no actual changes were made to +controls. In other words, the error was not associated with setting a particular +control. If it is another value, then only the controls up to <structfield>error_idx-1</structfield> +were modified and control <structfield>error_idx</structfield> is the one that +caused the error. The <structfield>error_idx</structfield> value is undefined +if the ioctl returned 0 (success).</entry> </row> <row> <entry>__u32</entry> @@ -312,10 +320,3 @@ to store the payload and this error code is returned.</para> </refsect1> </refentry> -<!-- -Local Variables: -mode: sgml -sgml-parent-document: "v4l2.sgml" -indent-tabs-mode: nil -End: ---> |