5.9. ioctl MEDIA_IOC_REQUEST_ALLOC¶
MEDIA_IOC_REQUEST_ALLOC - Allocate a request
int ioctl(int fd, MEDIA_IOC_REQUEST_ALLOC, int *argp)
File descriptor returned by
Pointer to an integer.
If the media device supports requests, then
this ioctl can be used to allocate a request. If it is not supported, then
errno is set to
ENOTTY. A request is accessed through a file descriptor
that is returned in
Finally, the file descriptor can be polled to wait for the request to complete.
5.9.5. Return Value¶
On success 0 is returned, on error -1 and the
errno variable is set
appropriately. The generic error codes are described at the
Generic Error Codes chapter.
The driver has no support for requests.