1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968"><title>Chapter 19. Generic Error Codes</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API"><link rel="up" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API"><link rel="prev" href="media-ioc-setup-link.html" title="ioctl MEDIA_IOC_SETUP_LINK"><link rel="next" href="fdl.html" title="Appendix M. GNU Free Documentation License"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 19. Generic Error Codes</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="media-ioc-setup-link.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="fdl.html">Next</a></td></tr></table><hr></div><div class="chapter"><div class="titlepage"><div><div><h1 class="title"><a name="gen_errors"></a>Chapter 19. Generic Error Codes</h1></div></div></div><div class="table"><a name="gen-errors"></a><p class="title"><b>Table 19.1. Generic error codes</b></p><div class="table-contents"><table summary="Generic error codes" width="100%" border="0"><colgroup><col class="c1"><col class="c2"></colgroup><tbody valign="top"><tr><td valign="top">EAGAIN (aka EWOULDBLOCK)</td><td valign="top">The ioctl can't be handled because the device is in state where 2 it can't perform it. This could happen for example in case where 3 device is sleeping and ioctl is performed to query statistics. 4 It is also returned when the ioctl would need to wait 5 for an event, but the device was opened in non-blocking mode. 6 </td></tr><tr><td valign="top">EBADF</td><td valign="top">The file descriptor is not a valid.</td></tr><tr><td valign="top">EBUSY</td><td valign="top">The ioctl can't be handled because the device is busy. This is 7 typically return while device is streaming, and an ioctl tried to 8 change something that would affect the stream, or would require the 9 usage of a hardware resource that was already allocated. The ioctl 10 must not be retried without performing another action to fix the 11 problem first (typically: stop the stream before retrying).</td></tr><tr><td valign="top">EFAULT</td><td valign="top">There was a failure while copying data from/to userspace, 12 probably caused by an invalid pointer reference.</td></tr><tr><td valign="top">EINVAL</td><td valign="top">One or more of the ioctl parameters are invalid or out of the 13 allowed range. This is a widely used error code. See the individual 14 ioctl requests for specific causes.</td></tr><tr><td valign="top">ENODEV</td><td valign="top">Device not found or was removed.</td></tr><tr><td valign="top">ENOMEM</td><td valign="top">There's not enough memory to handle the desired operation.</td></tr><tr><td valign="top">ENOTTY</td><td valign="top">The ioctl is not supported by the driver, actually meaning that 15 the required functionality is not available, or the file 16 descriptor is not for a media device.</td></tr><tr><td valign="top">ENOSPC</td><td valign="top">On USB devices, the stream ioctl's can return this error, meaning 17 that this request would overcommit the usb bandwidth reserved 18 for periodic transfers (up to 80% of the USB bandwidth).</td></tr><tr><td valign="top">EPERM</td><td valign="top">Permission denied. Can be returned if the device needs write 19 permission, or some special capabilities is needed 20 (e. g. root)</td></tr></tbody></table></div></div><br class="table-break"><p>Note 1: ioctls may return other error codes. Since errors may have side 21effects such as a driver reset, applications should abort on unexpected errors. 22</p><p>Note 2: Request-specific error codes are listed in the individual 23requests descriptions.</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="media-ioc-setup-link.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="fdl.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">ioctl MEDIA_IOC_SETUP_LINK </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Appendix M. GNU Free Documentation License</td></tr></table></div></body></html> 24