media: dvb: add continuity error indicators for memory mapped buffers

While userspace can detect discontinuity errors, it is useful to
also let Kernelspace reporting discontinuity, as it can help to
identify if the data loss happened either at Kernel or userspace side.

Update documentation accordingly.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab
2018-02-09 05:51:19 -05:00
parent 0b23498aac
commit 9c171cdf22
3 changed files with 49 additions and 7 deletions

View File

@@ -51,9 +51,10 @@ out to disk. Buffers remain locked until dequeued, until the
the device is closed.
Applications call the ``DMX_DQBUF`` ioctl to dequeue a filled
(capturing) buffer from the driver's outgoing queue. They just set the ``reserved`` field array to zero. When ``DMX_DQBUF`` is called with a
pointer to this structure, the driver fills the remaining fields or
returns an error code.
(capturing) buffer from the driver's outgoing queue.
They just set the ``index`` field withe the buffer ID to be queued.
When ``DMX_DQBUF`` is called with a pointer to struct :c:type:`dmx_buffer`,
the driver fills the remaining fields or returns an error code.
By default ``DMX_DQBUF`` blocks when no buffer is in the outgoing
queue. When the ``O_NONBLOCK`` flag was given to the