vb2_fileio_is_active — return true if fileio is active.
bool vb2_fileio_is_active ( | struct vb2_queue * q); |
This returns true if read or write is used to stream the data
as opposed to stream I/O. This is almost never an important distinction,
except in rare cases. One such case is that using read or write to
stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
is no way you can pass the field information of each buffer to/from
userspace. A driver that supports this field format should check for
this in the queue_setup op and reject it if this function returns true.