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Diffstat (limited to 'Documentation/media/uapi/dvb/dmx-fread.rst')
| -rw-r--r-- | Documentation/media/uapi/dvb/dmx-fread.rst | 78 |
1 files changed, 32 insertions, 46 deletions
diff --git a/Documentation/media/uapi/dvb/dmx-fread.rst b/Documentation/media/uapi/dvb/dmx-fread.rst index e8c7f4db353f..488bdc4ba178 100644 --- a/Documentation/media/uapi/dvb/dmx-fread.rst +++ b/Documentation/media/uapi/dvb/dmx-fread.rst @@ -2,14 +2,14 @@ .. _dmx_fread: -================ -DVB demux read() -================ +======================= +Digital TV demux read() +======================= Name ---- -DVB demux read() +Digital TV demux read() Synopsis @@ -33,62 +33,48 @@ Arguments Description ----------- -This system call returns filtered data, which might be section or PES -data. The filtered data is transferred from the driver’s internal -circular buffer to buf. The maximum amount of data to be transferred is -implied by count. +This system call returns filtered data, which might be section or Packetized +Elementary Stream (PES) data. The filtered data is transferred from +the driver’s internal circular buffer to ``buf``. The maximum amount of data +to be transferred is implied by count. + +.. note:: + + if a section filter created with + :c:type:`DMX_CHECK_CRC <dmx_sct_filter_params>` flag set, + data that fails on CRC check will be silently ignored. + Return Value ------------ +On success 0 is returned. + +On error -1 is returned, and the ``errno`` variable is set +appropriately. + .. tabularcolumns:: |p{2.5cm}|p{15.0cm}| .. flat-table:: :header-rows: 0 :stub-columns: 0 + :widths: 1 16 + - - ``EWOULDBLOCK`` + - No data to return and ``O_NONBLOCK`` was specified. - - .. row 1 - - - ``EWOULDBLOCK`` - - - No data to return and O_NONBLOCK was specified. - - - .. row 2 - - - ``EBADF`` - - - fd is not a valid open file descriptor. - - - .. row 3 - - - ``ECRC`` - - - Last section had a CRC error - no data returned. The buffer is - flushed. - - - .. row 4 - - - ``EOVERFLOW`` - - - - - - .. row 5 - - - + - - ``EOVERFLOW`` - The filtered data was not read from the buffer in due time, resulting in non-read data being lost. The buffer is flushed. - - .. row 6 - - - ``ETIMEDOUT`` - - - The section was not loaded within the stated timeout period. See - ioctl DMX_SET_FILTER for how to set a timeout. + - - ``ETIMEDOUT`` + - The section was not loaded within the stated timeout period. + See ioctl :ref:`DMX_SET_FILTER` for how to set a timeout. - - .. row 7 + - - ``EFAULT`` + - The driver failed to write to the callers buffer due to an + invalid \*buf pointer. - - ``EFAULT`` - - The driver failed to write to the callers buffer due to an invalid - \*buf pointer. +The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. |