MEDIA_IOC_SETUP_LINK — Modify the properties of a link
int ioctl( | int fd, |
| int request, | |
struct media_link_desc *argp); |
To change link properties applications fill a struct media_link_desc with link identification information (source and sink pad) and the new requested link flags. They then call the MEDIA_IOC_SETUP_LINK ioctl with a pointer to that structure.
The only configurable property is the ENABLED
link flag to enable/disable a link. Links marked with the
IMMUTABLE link flag can not be enabled or disabled.
Link configuration has no side effect on other links. If an enabled link at the sink pad prevents the link from being enabled, the driver returns with an EBUSY error code.
Only links marked with the DYNAMIC link flag can
be enabled/disabled while streaming media data. Attempting to enable or
disable a streaming non-dynamic link will return an EBUSY error code.
If the specified link can't be found the driver returns with an EINVAL error code.
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 struct media_link_desc references a non-existing link, or the link is immutable and an attempt to modify its configuration was made.