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40>Video for Linux Two API Specification: Revision 0.24</TH
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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&nbsp;--&nbsp;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
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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
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