NAME

       gensio_set_read_callback_enable, gensio_set_write_callback_enable - Enable or disable read data and write
       ready

SYNOPSIS

       #include <gensio/gensio.h>

       void gensio_set_read_callback_enable(struct gensio *io,
                           bool enabled);

       void gensio_set_write_callback_enable(struct gensio *io,
                           bool enabled);

DESCRIPTION

       These  function  enable  the  write  callback, or the read callback, for gensios (and all child gensios).
       Generally disabling the read callback will disable all callbacks except write because  it  won't  receive
       any data to do any processing.

       After  you  open  a  gensio  or  receive a gensio from an accepter, the gensio has all the enables set to
       false.  You would generally want to enable the read callback and leave it enabled as much as possible  so
       that  low-level processing will happen on the gensio.  In particular, disabling read on a UDP gensio will
       disable all read an accept processing.

       Enabling the write callback will enable the callback to tell you if the gensio can  currently  write  any
       data.   You normally want to leave this disabled and enable it if you write data and get a partial write.
       Or even better, when you have data to write, enable the write  callback  and  write  the  data  from  the
       callback, disabling when it is all written.

       Disabling  the  write  callback does not necessarily keep data from being transmitted by the gensio.  The
       SSL gensio, for instance, may transmit key information on a rekey, or other gensios  may  transmit  flow-
       control information.  This only affects the write callback.

       Disabling  the  callbacks  may  not be immediate.  "Immediate" is hard to define in a SMP system, anyway.
       There may be callbacks running or about to be called when you disable the callback, they may  still  run.
       You must be prepared to handle these race conditions.

RETURN VALUES

       Zero is returned on success, or a gensio error on failure.

SEE ALSO

       gensio_err(3), gensio(5)

                                                   27 Feb 2019                gensio_set_read_callback_enable(3)