ioctl MEDIA_IOC_SETUP_LINK
&manvol;

# MEDIA_IOC_SETUP_LINK

Modify the properties of a link

    	int ioctl
    	int fd
    	int request
    	struct media_link_desc *argp

## Arguments

`fd`

  File descriptor returned by `open()`.

`request`

  MEDIA_IOC_SETUP_LINK

`argp`

## Description

To change link properties applications fill a &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;.

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;.

If the specified link can't be found the driver returns with an &EINVAL;.

&return-value;

EBUSY

  The link properties can't be changed because the link is currently busy. This can be caused, for instance, by an active media stream (audio or video) on the link. The ioctl shouldn't be retried if no other action is performed before to fix the problem.

EINVAL

  The &media-link-desc; references a non-existing link, or the link is immutable and an attempt to modify its configuration was made.