Based on kernel version 4.7.2. Page generated on 2016-08-22 22:45 EST.
1 <title>Generic Error Codes</title> 2 3 <table frame="none" pgwide="1" id="gen-errors"> 4 <title>Generic error codes</title> 5 <tgroup cols="2"> 6 &cs-str; 7 <tbody valign="top"> 8 <!-- Keep it ordered alphabetically --> 9 <row> 10 <entry>EAGAIN (aka EWOULDBLOCK)</entry> 11 <entry>The ioctl can't be handled because the device is in state where 12 it can't perform it. This could happen for example in case where 13 device is sleeping and ioctl is performed to query statistics. 14 It is also returned when the ioctl would need to wait 15 for an event, but the device was opened in non-blocking mode. 16 </entry> 17 </row> 18 <row> 19 <entry>EBADF</entry> 20 <entry>The file descriptor is not a valid.</entry> 21 </row> 22 <row> 23 <entry>EBUSY</entry> 24 <entry>The ioctl can't be handled because the device is busy. This is 25 typically return while device is streaming, and an ioctl tried to 26 change something that would affect the stream, or would require the 27 usage of a hardware resource that was already allocated. The ioctl 28 must not be retried without performing another action to fix the 29 problem first (typically: stop the stream before retrying).</entry> 30 </row> 31 <row> 32 <entry>EFAULT</entry> 33 <entry>There was a failure while copying data from/to userspace, 34 probably caused by an invalid pointer reference.</entry> 35 </row> 36 <row> 37 <entry>EINVAL</entry> 38 <entry>One or more of the ioctl parameters are invalid or out of the 39 allowed range. This is a widely used error code. See the individual 40 ioctl requests for specific causes.</entry> 41 </row> 42 <row> 43 <entry>ENODEV</entry> 44 <entry>Device not found or was removed.</entry> 45 </row> 46 <row> 47 <entry>ENOMEM</entry> 48 <entry>There's not enough memory to handle the desired operation.</entry> 49 </row> 50 <row> 51 <entry>ENOTTY</entry> 52 <entry>The ioctl is not supported by the driver, actually meaning that 53 the required functionality is not available, or the file 54 descriptor is not for a media device.</entry> 55 </row> 56 <row> 57 <entry>ENOSPC</entry> 58 <entry>On USB devices, the stream ioctl's can return this error, meaning 59 that this request would overcommit the usb bandwidth reserved 60 for periodic transfers (up to 80% of the USB bandwidth).</entry> 61 </row> 62 <row> 63 <entry>EPERM</entry> 64 <entry>Permission denied. Can be returned if the device needs write 65 permission, or some special capabilities is needed 66 (e. g. root)</entry> 67 </row> 68 </tbody> 69 </tgroup> 70 </table> 71 72 <para>Note 1: ioctls may return other error codes. Since errors may have side 73 effects such as a driver reset, applications should abort on unexpected errors. 74 </para> 75 76 <para>Note 2: Request-specific error codes are listed in the individual 77 requests descriptions.</para>