1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> 2<HTML 3><HEAD 4><TITLE 5>ioctl VIDIOC_LOG_STATUS</TITLE 6><META 7NAME="GENERATOR" 8CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK 9REL="HOME" 10TITLE="Video for Linux Two API Specification" 11HREF="book1.htm"><LINK 12REL="UP" 13TITLE="Function Reference" 14HREF="r7624.htm"><LINK 15REL="PREVIOUS" 16TITLE="ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER" 17HREF="r12342.htm"><LINK 18REL="NEXT" 19TITLE="ioctl VIDIOC_OVERLAY" 20HREF="r12816.htm"></HEAD 21><BODY 22CLASS="REFENTRY" 23BGCOLOR="#FFFFFF" 24TEXT="#000000" 25LINK="#0000FF" 26VLINK="#840084" 27ALINK="#0000FF" 28><DIV 29CLASS="NAVHEADER" 30><TABLE 31SUMMARY="Header navigation table" 32WIDTH="100%" 33BORDER="0" 34CELLPADDING="0" 35CELLSPACING="0" 36><TR 37><TH 38COLSPAN="3" 39ALIGN="center" 40>Video for Linux Two API Specification: Revision 0.24</TH 41></TR 42><TR 43><TD 44WIDTH="10%" 45ALIGN="left" 46VALIGN="bottom" 47><A 48HREF="r12342.htm" 49ACCESSKEY="P" 50>Prev</A 51></TD 52><TD 53WIDTH="80%" 54ALIGN="center" 55VALIGN="bottom" 56></TD 57><TD 58WIDTH="10%" 59ALIGN="right" 60VALIGN="bottom" 61><A 62HREF="r12816.htm" 63ACCESSKEY="N" 64>Next</A 65></TD 66></TR 67></TABLE 68><HR 69ALIGN="LEFT" 70WIDTH="100%"></DIV 71><H1 72><A 73NAME="VIDIOC-LOG-STATUS" 74></A 75>ioctl VIDIOC_LOG_STATUS</H1 76><DIV 77CLASS="REFNAMEDIV" 78><A 79NAME="AEN12788" 80></A 81><H2 82>Name</H2 83>VIDIOC_LOG_STATUS -- Log driver status information</DIV 84><DIV 85CLASS="REFSYNOPSISDIV" 86><A 87NAME="AEN12791" 88></A 89><H2 90>Synopsis</H2 91><DIV 92CLASS="FUNCSYNOPSIS" 93><P 94></P 95><A 96NAME="AEN12792" 97></A 98><P 99><CODE 100><CODE 101CLASS="FUNCDEF" 102>int ioctl</CODE 103>(int fd, int request);</CODE 104></P 105><P 106></P 107></DIV 108></DIV 109><DIV 110CLASS="REFSECT1" 111><A 112NAME="AEN12800" 113></A 114><H2 115>Description</H2 116><P 117>As the video/audio devices become more complicated it 118becomes harder to debug problems. When this ioctl is called the driver 119will output the current device status to the kernel log. This is 120particular useful when dealing with problems like no sound, no video 121and incorrectly tuned channels. Also many modern devices autodetect 122video and audio standards and this ioctl will report what the device 123thinks what the standard is. Mismatches may give an indication where 124the problem is.</P 125><P 126>This ioctl is optional and not all drivers support it. It 127was introduced in Linux 2.6.15.</P 128></DIV 129><DIV 130CLASS="REFSECT1" 131><A 132NAME="AEN12804" 133></A 134><H2 135>Return Value</H2 136><P 137>On success <SPAN 138CLASS="RETURNVALUE" 139>0</SPAN 140> is returned, on error <SPAN 141CLASS="RETURNVALUE" 142>-1</SPAN 143> and the <CODE 144CLASS="VARNAME" 145>errno</CODE 146> variable is set appropriately:</P 147><P 148></P 149><DIV 150CLASS="VARIABLELIST" 151><DL 152><DT 153><SPAN 154CLASS="ERRORCODE" 155>EINVAL</SPAN 156></DT 157><DD 158><P 159>The driver does not support this ioctl.</P 160></DD 161></DL 162></DIV 163></DIV 164><DIV 165CLASS="NAVFOOTER" 166><HR 167ALIGN="LEFT" 168WIDTH="100%"><TABLE 169SUMMARY="Footer navigation table" 170WIDTH="100%" 171BORDER="0" 172CELLPADDING="0" 173CELLSPACING="0" 174><TR 175><TD 176WIDTH="33%" 177ALIGN="left" 178VALIGN="top" 179><A 180HREF="r12342.htm" 181ACCESSKEY="P" 182>Prev</A 183></TD 184><TD 185WIDTH="34%" 186ALIGN="center" 187VALIGN="top" 188><A 189HREF="book1.htm" 190ACCESSKEY="H" 191>Home</A 192></TD 193><TD 194WIDTH="33%" 195ALIGN="right" 196VALIGN="top" 197><A 198HREF="r12816.htm" 199ACCESSKEY="N" 200>Next</A 201></TD 202></TR 203><TR 204><TD 205WIDTH="33%" 206ALIGN="left" 207VALIGN="top" 208>ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</TD 209><TD 210WIDTH="34%" 211ALIGN="center" 212VALIGN="top" 213><A 214HREF="r7624.htm" 215ACCESSKEY="U" 216>Up</A 217></TD 218><TD 219WIDTH="33%" 220ALIGN="right" 221VALIGN="top" 222>ioctl VIDIOC_OVERLAY</TD 223></TR 224></TABLE 225></DIV 226></BODY 227></HTML 228> 229