4.8. ioctl MEDIA_IOC_SETUP_LINK¶
4.8.1. Name¶
MEDIA_IOC_SETUP_LINK - Modify the properties of a link
4.8.4. Description¶
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.
4.8.5. 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.
- EINVAL
- The struct media_link_desc references a non-existing link, or the link is immutable and an attempt to modify its configuration was made.