diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-13 19:09:57 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-13 19:09:57 (GMT) |
commit | 858655116bfc722837e3aec0909b8e9d08f96996 (patch) | |
tree | ef9171d51ffcd01e40d1131d62be32e5a7d371dc /Documentation/DocBook | |
parent | 239dab4636f7f5f971ac39b5ca84254cff112cac (diff) | |
parent | 1b2c14b44adcb7836528640bfdc40bf7499d987d (diff) | |
download | linux-858655116bfc722837e3aec0909b8e9d08f96996.tar.xz |
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:
"This series contain:
- new i2c video drivers: ml86v7667 (video decoder),
ths8200 (video encoder)
- a new video driver for EasyCap cards based on Fushicai USBTV007
- Improved support for OF and embedded systems, with V4L2 async
initialization and a better support for clocks
- API cleanups on the ioctls used by the v4l2 debug tool
- Lots of cleanups
- As usual, several driver improvements and new cards additions
- Revert two changesets that change the minimal symbol rate for
stv0399, as request by Manu
- Update MAINTAINERS and other files to point to my new e-mail"
* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (378 commits)
MAINTAINERS & ABI: Update to point to my new email
[media] stb0899: restore minimal rate to 5Mbauds
[media] exynos4-is: Correct colorspace handling at FIMC-LITE
[media] exynos4-is: Set valid initial format on FIMC.n subdevs
[media] exynos4-is: Set valid initial format on FIMC-IS-ISP subdev pads
[media] exynos4-is: Fix format propagation on FIMC-IS-ISP subdev
[media] exynos4-is: Set valid initial format at FIMC-LITE
[media] exynos4-is: Fix format propagation on FIMC-LITE.n subdevs
[media] MAINTAINERS: Update S5P/Exynos FIMC driver entry
[media] Documentation: Update driver's directory in video4linux/fimc.txt
[media] exynos4-is: Change fimc-is firmware file names
[media] exynos4-is: Add support for Exynos5250 MIPI-CSIS
[media] exynos4-is: Add Exynos5250 SoC support to fimc-lite driver
[media] exynos4-is: Drop drvdata handling in fimc-lite for non-dt platforms
[media] media: i2c: tvp514x: remove manual setting of subdev name
[media] media: i2c: tvp7002: remove manual setting of subdev name
[media] mem2mem: set missing v4l2_dev pointer
[media] wl128x: add missing struct v4l2_device
[media] tvp514x: Fix init seqeunce
[media] saa7134: Fix sparse warnings by adding __user annotation
...
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r-- | Documentation/DocBook/media/v4l/compat.xml | 14 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/v4l2.xml | 11 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-ident.xml | 271 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-info.xml | 20 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml | 64 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-querystd.xml | 3 |
6 files changed, 37 insertions, 346 deletions
diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index f43542a..0c7195e 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2254,7 +2254,7 @@ video encoding.</para> <orderedlist> <listitem> <para>The <constant>VIDIOC_G_CHIP_IDENT</constant> ioctl was renamed -to <constant>VIDIOC_G_CHIP_IDENT_OLD</constant> and &VIDIOC-DBG-G-CHIP-IDENT; +to <constant>VIDIOC_G_CHIP_IDENT_OLD</constant> and <constant>VIDIOC_DBG_G_CHIP_IDENT</constant> was introduced in its place. The old struct <structname>v4l2_chip_ident</structname> was renamed to <structname id="v4l2-chip-ident-old">v4l2_chip_ident_old</structname>.</para> </listitem> @@ -2513,6 +2513,16 @@ that used it. It was originally scheduled for removal in 2.6.35. </orderedlist> </section> + <section> + <title>V4L2 in Linux 3.11</title> + <orderedlist> + <listitem> + <para>Remove obsolete <constant>VIDIOC_DBG_G_CHIP_IDENT</constant> ioctl. + </para> + </listitem> + </orderedlist> + </section> + <section id="other"> <title>Relation of V4L2 to other Linux multimedia APIs</title> @@ -2596,7 +2606,7 @@ and may change in the future.</para> ioctls.</para> </listitem> <listitem> - <para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para> + <para>&VIDIOC-DBG-G-CHIP-INFO; ioctl.</para> </listitem> <listitem> <para>&VIDIOC-ENUM-DV-TIMINGS;, &VIDIOC-QUERY-DV-TIMINGS; and diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index bfe823d..8469fe1 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -141,6 +141,14 @@ structs, ioctls) must be noted in more detail in the history chapter applications. --> <revision> + <revnumber>3.11</revnumber> + <date>2013-05-26</date> + <authorinitials>hv</authorinitials> + <revremark>Remove obsolete VIDIOC_DBG_G_CHIP_IDENT ioctl. + </revremark> + </revision> + + <revision> <revnumber>3.10</revnumber> <date>2013-03-25</date> <authorinitials>hv</authorinitials> @@ -493,7 +501,7 @@ and discussions on the V4L mailing list.</revremark> </partinfo> <title>Video for Linux Two API Specification</title> - <subtitle>Revision 3.10</subtitle> + <subtitle>Revision 3.11</subtitle> <chapter id="common"> &sub-common; @@ -547,7 +555,6 @@ and discussions on the V4L mailing list.</revremark> <!-- All ioctls go here. --> &sub-create-bufs; &sub-cropcap; - &sub-dbg-g-chip-ident; &sub-dbg-g-chip-info; &sub-dbg-g-register; &sub-decoder-cmd; diff --git a/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-ident.xml b/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-ident.xml deleted file mode 100644 index 921e185..0000000 --- a/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-ident.xml +++ /dev/null @@ -1,271 +0,0 @@ -<refentry id="vidioc-dbg-g-chip-ident"> - <refmeta> - <refentrytitle>ioctl VIDIOC_DBG_G_CHIP_IDENT</refentrytitle> - &manvol; - </refmeta> - - <refnamediv> - <refname>VIDIOC_DBG_G_CHIP_IDENT</refname> - <refpurpose>Identify the chips on a TV card</refpurpose> - </refnamediv> - - <refsynopsisdiv> - <funcsynopsis> - <funcprototype> - <funcdef>int <function>ioctl</function></funcdef> - <paramdef>int <parameter>fd</parameter></paramdef> - <paramdef>int <parameter>request</parameter></paramdef> - <paramdef>struct v4l2_dbg_chip_ident -*<parameter>argp</parameter></paramdef> - </funcprototype> - </funcsynopsis> - </refsynopsisdiv> - - <refsect1> - <title>Arguments</title> - - <variablelist> - <varlistentry> - <term><parameter>fd</parameter></term> - <listitem> - <para>&fd;</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>request</parameter></term> - <listitem> - <para>VIDIOC_DBG_G_CHIP_IDENT</para> - </listitem> - </varlistentry> - <varlistentry> - <term><parameter>argp</parameter></term> - <listitem> - <para></para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> - - <refsect1> - <title>Description</title> - - <note> - <title>Experimental</title> - - <para>This is an <link -linkend="experimental">experimental</link> interface and may change in -the future.</para> - </note> - - <para>For driver debugging purposes this ioctl allows test -applications to query the driver about the chips present on the TV -card. Regular applications must not use it. When you found a chip -specific bug, please contact the linux-media mailing list (&v4l-ml;) -so it can be fixed.</para> - - <para>To query the driver applications must initialize the -<structfield>match.type</structfield> and -<structfield>match.addr</structfield> or <structfield>match.name</structfield> -fields of a &v4l2-dbg-chip-ident; -and call <constant>VIDIOC_DBG_G_CHIP_IDENT</constant> with a pointer to -this structure. On success the driver stores information about the -selected chip in the <structfield>ident</structfield> and -<structfield>revision</structfield> fields. On failure the structure -remains unchanged.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_HOST</constant>, -<structfield>match.addr</structfield> selects the nth non-&i2c; chip -on the TV card. You can enumerate all chips by starting at zero and -incrementing <structfield>match.addr</structfield> by one until -<constant>VIDIOC_DBG_G_CHIP_IDENT</constant> fails with an &EINVAL;. -The number zero always selects the host chip, ⪚ the chip connected -to the PCI or USB bus.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant>, -<structfield>match.name</structfield> contains the I2C driver name. -For instance -<constant>"saa7127"</constant> will match any chip -supported by the saa7127 driver, regardless of its &i2c; bus address. -When multiple chips supported by the same driver are present, the -ioctl will return <constant>V4L2_IDENT_AMBIGUOUS</constant> in the -<structfield>ident</structfield> field.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_ADDR</constant>, -<structfield>match.addr</structfield> selects a chip by its 7 bit -&i2c; bus address.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_AC97</constant>, -<structfield>match.addr</structfield> selects the nth AC97 chip -on the TV card. You can enumerate all chips by starting at zero and -incrementing <structfield>match.addr</structfield> by one until -<constant>VIDIOC_DBG_G_CHIP_IDENT</constant> fails with an &EINVAL;.</para> - - <para>On success, the <structfield>ident</structfield> field will -contain a chip ID from the Linux -<filename>media/v4l2-chip-ident.h</filename> header file, and the -<structfield>revision</structfield> field will contain a driver -specific value, or zero if no particular revision is associated with -this chip.</para> - - <para>When the driver could not identify the selected chip, -<structfield>ident</structfield> will contain -<constant>V4L2_IDENT_UNKNOWN</constant>. When no chip matched -the ioctl will succeed but the -<structfield>ident</structfield> field will contain -<constant>V4L2_IDENT_NONE</constant>. If multiple chips matched, -<structfield>ident</structfield> will contain -<constant>V4L2_IDENT_AMBIGUOUS</constant>. In all these cases the -<structfield>revision</structfield> field remains unchanged.</para> - - <para>This ioctl is optional, not all drivers may support it. It -was introduced in Linux 2.6.21, but the API was changed to the -one described here in 2.6.29.</para> - - <para>We recommended the <application>v4l2-dbg</application> -utility over calling this ioctl directly. It is available from the -LinuxTV v4l-dvb repository; see <ulink -url="http://linuxtv.org/repo/">http://linuxtv.org/repo/</ulink> for -access instructions.</para> - - <!-- Note for convenience vidioc-dbg-g-register.sgml - contains a duplicate of this table. --> - <table pgwide="1" frame="none" id="ident-v4l2-dbg-match"> - <title>struct <structname>v4l2_dbg_match</structname></title> - <tgroup cols="4"> - &cs-ustr; - <tbody valign="top"> - <row> - <entry>__u32</entry> - <entry><structfield>type</structfield></entry> - <entry>See <xref linkend="ident-chip-match-types" /> for a list of -possible types.</entry> - </row> - <row> - <entry>union</entry> - <entry>(anonymous)</entry> - </row> - <row> - <entry></entry> - <entry>__u32</entry> - <entry><structfield>addr</structfield></entry> - <entry>Match a chip by this number, interpreted according -to the <structfield>type</structfield> field.</entry> - </row> - <row> - <entry></entry> - <entry>char</entry> - <entry><structfield>name[32]</structfield></entry> - <entry>Match a chip by this name, interpreted according -to the <structfield>type</structfield> field.</entry> - </row> - </tbody> - </tgroup> - </table> - - <table pgwide="1" frame="none" id="v4l2-dbg-chip-ident"> - <title>struct <structname>v4l2_dbg_chip_ident</structname></title> - <tgroup cols="3"> - &cs-str; - <tbody valign="top"> - <row> - <entry>struct v4l2_dbg_match</entry> - <entry><structfield>match</structfield></entry> - <entry>How to match the chip, see <xref linkend="ident-v4l2-dbg-match" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>ident</structfield></entry> - <entry>A chip identifier as defined in the Linux -<filename>media/v4l2-chip-ident.h</filename> header file, or one of -the values from <xref linkend="chip-ids" />.</entry> - </row> - <row> - <entry>__u32</entry> - <entry><structfield>revision</structfield></entry> - <entry>A chip revision, chip and driver specific.</entry> - </row> - </tbody> - </tgroup> - </table> - - <!-- Note for convenience vidioc-dbg-g-register.sgml - contains a duplicate of this table. --> - <table pgwide="1" frame="none" id="ident-chip-match-types"> - <title>Chip Match Types</title> - <tgroup cols="3"> - &cs-def; - <tbody valign="top"> - <row> - <entry><constant>V4L2_CHIP_MATCH_BRIDGE</constant></entry> - <entry>0</entry> - <entry>Match the nth chip on the card, zero for the - bridge chip. Does not match sub-devices.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry> - <entry>1</entry> - <entry>Match an &i2c; chip by its driver name.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_ADDR</constant></entry> - <entry>2</entry> - <entry>Match a chip by its 7 bit &i2c; bus address.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry> - <entry>3</entry> - <entry>Match the nth anciliary AC97 chip.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_SUBDEV</constant></entry> - <entry>4</entry> - <entry>Match the nth sub-device. Can't be used with this ioctl.</entry> - </row> - </tbody> - </tgroup> - </table> - - <!-- This is an anonymous enum in media/v4l2-chip-ident.h. --> - <table pgwide="1" frame="none" id="chip-ids"> - <title>Chip Identifiers</title> - <tgroup cols="3"> - &cs-def; - <tbody valign="top"> - <row> - <entry><constant>V4L2_IDENT_NONE</constant></entry> - <entry>0</entry> - <entry>No chip matched.</entry> - </row> - <row> - <entry><constant>V4L2_IDENT_AMBIGUOUS</constant></entry> - <entry>1</entry> - <entry>Multiple chips matched.</entry> - </row> - <row> - <entry><constant>V4L2_IDENT_UNKNOWN</constant></entry> - <entry>2</entry> - <entry>A chip is present at this address, but the driver -could not identify it.</entry> - </row> - </tbody> - </tgroup> - </table> - </refsect1> - - <refsect1> - &return-value; - - <variablelist> - <varlistentry> - <term><errorcode>EINVAL</errorcode></term> - <listitem> - <para>The <structfield>match_type</structfield> is invalid.</para> - </listitem> - </varlistentry> - </variablelist> - </refsect1> -</refentry> diff --git a/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-info.xml b/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-info.xml index e1cece6..4c4603c 100644 --- a/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-info.xml +++ b/Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-info.xml @@ -73,8 +73,7 @@ fields of a &v4l2-dbg-chip-info; and call <constant>VIDIOC_DBG_G_CHIP_INFO</constant> with a pointer to this structure. On success the driver stores information about the selected chip in the <structfield>name</structfield> and -<structfield>flags</structfield> fields. On failure the structure -remains unchanged.</para> +<structfield>flags</structfield> fields.</para> <para>When <structfield>match.type</structfield> is <constant>V4L2_CHIP_MATCH_BRIDGE</constant>, @@ -132,7 +131,7 @@ to the <structfield>type</structfield> field.</entry> <entry>char</entry> <entry><structfield>name[32]</structfield></entry> <entry>Match a chip by this name, interpreted according -to the <structfield>type</structfield> field.</entry> +to the <structfield>type</structfield> field. Currently unused.</entry> </row> </tbody> </tgroup> @@ -183,21 +182,6 @@ is set, then the driver supports reading registers from the device. If bridge chip. Does not match sub-devices.</entry> </row> <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry> - <entry>1</entry> - <entry>Match an &i2c; chip by its driver name. Can't be used with this ioctl.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_ADDR</constant></entry> - <entry>2</entry> - <entry>Match a chip by its 7 bit &i2c; bus address. Can't be used with this ioctl.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry> - <entry>3</entry> - <entry>Match the nth anciliary AC97 chip. Can't be used with this ioctl.</entry> - </row> - <row> <entry><constant>V4L2_CHIP_MATCH_SUBDEV</constant></entry> <entry>4</entry> <entry>Match the nth sub-device.</entry> diff --git a/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml b/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml index d13bac9..3d038e7 100644 --- a/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml +++ b/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml @@ -76,7 +76,7 @@ compiled with the <constant>CONFIG_VIDEO_ADV_DEBUG</constant> option to enable these ioctls.</para> <para>To write a register applications must initialize all fields -of a &v4l2-dbg-register; and call +of a &v4l2-dbg-register; except for <structfield>size</structfield> and call <constant>VIDIOC_DBG_S_REGISTER</constant> with a pointer to this structure. The <structfield>match.type</structfield> and <structfield>match.addr</structfield> or <structfield>match.name</structfield> @@ -91,8 +91,8 @@ written into the register.</para> <structfield>reg</structfield> fields, and call <constant>VIDIOC_DBG_G_REGISTER</constant> with a pointer to this structure. On success the driver stores the register value in the -<structfield>val</structfield> field. On failure the structure remains -unchanged.</para> +<structfield>val</structfield> field and the size (in bytes) of the +value in <structfield>size</structfield>.</para> <para>When <structfield>match.type</structfield> is <constant>V4L2_CHIP_MATCH_BRIDGE</constant>, @@ -102,39 +102,9 @@ chip connected to the PCI or USB bus. You can find out which chips are present with the &VIDIOC-DBG-G-CHIP-INFO; ioctl.</para> <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant>, -<structfield>match.name</structfield> contains the I2C driver name. -For instance -<constant>"saa7127"</constant> will match any chip -supported by the saa7127 driver, regardless of its &i2c; bus address. -When multiple chips supported by the same driver are present, the -effect of these ioctls is undefined. Again with the -&VIDIOC-DBG-G-CHIP-INFO; ioctl you can find out which &i2c; chips are -present.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_ADDR</constant>, -<structfield>match.addr</structfield> selects a chip by its 7 bit &i2c; -bus address.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_AC97</constant>, -<structfield>match.addr</structfield> selects the nth AC97 chip -on the TV card.</para> - - <para>When <structfield>match.type</structfield> is <constant>V4L2_CHIP_MATCH_SUBDEV</constant>, <structfield>match.addr</structfield> selects the nth sub-device.</para> - <note> - <title>Success not guaranteed</title> - - <para>Due to a flaw in the Linux &i2c; bus driver these ioctls may -return successfully without actually reading or writing a register. To -catch the most likely failure we recommend a &VIDIOC-DBG-G-CHIP-INFO; -call confirming the presence of the selected &i2c; chip.</para> - </note> - <para>These ioctls are optional, not all drivers may support them. However when a driver supports these ioctls it must also support &VIDIOC-DBG-G-CHIP-INFO;. Conversely it may support @@ -150,7 +120,7 @@ LinuxTV v4l-dvb repository; see <ulink url="http://linuxtv.org/repo/">http://linuxtv.org/repo/</ulink> for access instructions.</para> - <!-- Note for convenience vidioc-dbg-g-chip-ident.sgml + <!-- Note for convenience vidioc-dbg-g-chip-info.sgml contains a duplicate of this table. --> <table pgwide="1" frame="none" id="v4l2-dbg-match"> <title>struct <structname>v4l2_dbg_match</structname></title> @@ -160,7 +130,7 @@ access instructions.</para> <row> <entry>__u32</entry> <entry><structfield>type</structfield></entry> - <entry>See <xref linkend="ident-chip-match-types" /> for a list of + <entry>See <xref linkend="chip-match-types" /> for a list of possible types.</entry> </row> <row> @@ -179,7 +149,7 @@ to the <structfield>type</structfield> field.</entry> <entry>char</entry> <entry><structfield>name[32]</structfield></entry> <entry>Match a chip by this name, interpreted according -to the <structfield>type</structfield> field.</entry> +to the <structfield>type</structfield> field. Currently unused.</entry> </row> </tbody> </tgroup> @@ -199,6 +169,11 @@ to the <structfield>type</structfield> field.</entry> <entry>How to match the chip, see <xref linkend="v4l2-dbg-match" />.</entry> </row> <row> + <entry>__u32</entry> + <entry><structfield>size</structfield></entry> + <entry>The register size in bytes.</entry> + </row> + <row> <entry>__u64</entry> <entry><structfield>reg</structfield></entry> <entry>A register number.</entry> @@ -213,7 +188,7 @@ register.</entry> </tgroup> </table> - <!-- Note for convenience vidioc-dbg-g-chip-ident.sgml + <!-- Note for convenience vidioc-dbg-g-chip-info.sgml contains a duplicate of this table. --> <table pgwide="1" frame="none" id="chip-match-types"> <title>Chip Match Types</title> @@ -227,21 +202,6 @@ register.</entry> bridge chip. Does not match sub-devices.</entry> </row> <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry> - <entry>1</entry> - <entry>Match an &i2c; chip by its driver name.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_I2C_ADDR</constant></entry> - <entry>2</entry> - <entry>Match a chip by its 7 bit &i2c; bus address.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry> - <entry>3</entry> - <entry>Match the nth anciliary AC97 chip.</entry> - </row> - <row> <entry><constant>V4L2_CHIP_MATCH_SUBDEV</constant></entry> <entry>4</entry> <entry>Match the nth sub-device.</entry> diff --git a/Documentation/DocBook/media/v4l/vidioc-querystd.xml b/Documentation/DocBook/media/v4l/vidioc-querystd.xml index fe80a18..2223485 100644 --- a/Documentation/DocBook/media/v4l/vidioc-querystd.xml +++ b/Documentation/DocBook/media/v4l/vidioc-querystd.xml @@ -54,7 +54,8 @@ standard automatically. To do so, applications call <constant> VIDIOC_QUERYSTD</constant> with a pointer to a &v4l2-std-id; type. The driver stores here a set of candidates, this can be a single flag or a set of supported standards if for example the hardware can only -distinguish between 50 and 60 Hz systems. When detection is not +distinguish between 50 and 60 Hz systems. If no signal was detected, +then the driver will return V4L2_STD_UNKNOWN. When detection is not possible or fails, the set must contain all standards supported by the current video input or output.</para> |