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linux-next/Documentation/DocBook/media/dvb/fe-read-status.xml
Mauro Carvalho Chehab d27518ca0c [media] DocBook: fix FE_READ_STATUS argument description
What's written there about the arguments for this ioctl
is bogus: it doesn't return an enum (or a typedef)
for enum fe_status. Instead, it returns a bitmask with the
values defined by enum fe_status.

Also, the size of the integer returned is not 16 bits, but,
instead, sizeof(fe_status_t), e. g. sizeof(enum), with is
arch-dependent.

This should of course be fixed, but this should be done on
a separate patch.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-05-30 09:43:09 -03:00

108 lines
3.2 KiB
XML

<refentry id="FE_READ_STATUS">
<refmeta>
<refentrytitle>ioctl FE_READ_STATUS</refentrytitle>
&manvol;
</refmeta>
<refnamediv>
<refname>FE_READ_STATUS</refname>
<refpurpose>Returns status information about the front-end. This call only
requires read-only access to the device</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<funcdef>int <function>ioctl</function></funcdef>
<paramdef>int <parameter>fd</parameter></paramdef>
<paramdef>int <parameter>request</parameter></paramdef>
<paramdef>unsigned int *<parameter>status</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Arguments</title>
<variablelist>
<varlistentry>
<term><parameter>fd</parameter></term>
<listitem>
<para>&fe_fd;</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>request</parameter></term>
<listitem>
<para>FE_READ_STATUS</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>status</parameter></term>
<listitem>
<para>pointer to a bitmask integer filled with the values defined by
&fe-status;.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Description</title>
<para>All DVB frontend devices support the
<constant>FE_READ_STATUS</constant> ioctl. It is used to check about the
locking status of the frontend after being tuned. The ioctl takes a
pointer to an integer where the status will be written.
</para>
<para>NOTE: the size of status is actually sizeof(enum fe_status), with varies
according with the architecture. This needs to be fixed in the future.</para>
&return-value-dvb;
</refsect1>
<section id="fe-status-t">
<title>int fe_status</title>
<para>The fe_status parameter is used to indicate the current state
and/or state changes of the frontend hardware. It is produced using
the &fe-status; values on a bitmask</para>
<table pgwide="1" frame="none" id="fe-status">
<title>enum fe_status</title>
<tgroup cols="2">
&cs-def;
<thead>
<row>
<entry>ID</entry>
<entry>Description</entry>
</row>
</thead>
<tbody valign="top">
<row>
<entry align="char">FE_HAS_SIGNAL</entry>
<entry align="char">The frontend has found something above the noise level</entry>
</row><row>
<entry align="char">FE_HAS_CARRIER</entry>
<entry align="char">The frontend has found a DVB signal</entry>
</row><row>
<entry align="char">FE_HAS_VITERBI</entry>
<entry align="char">The frontend FEC inner coding (Viterbi, LDPC or other inner code) is stable</entry>
</row><row>
<entry align="char">FE_HAS_SYNC</entry>
<entry align="char">Synchronization bytes was found</entry>
</row><row>
<entry align="char">FE_HAS_LOCK</entry>
<entry align="char">The DVB were locked and everything is working</entry>
</row><row>
<entry align="char">FE_TIMEDOUT</entry>
<entry align="char">no lock within the last about 2 seconds</entry>
</row><row>
<entry align="char">FE_REINIT</entry>
<entry align="char">The frontend was reinitialized, application is
recommended to reset DiSEqC, tone and parameters</entry>
</row>
</tbody>
</tgroup>
</table>
</section>
</refentry>