On Fri, 8 Apr 2022, Ilpo Järvinen wrote:
> On Fri, 8 Apr 2022, Andy Shevchenko wrote:
>
> > On Fri, Apr 08, 2022 at 02:39:53PM +0300, Ilpo Järvinen wrote:
> > > After lookahead for XON/XOFF characters is added by the next
> > > patch, the receive side needs to ensure the flow-control
> > > actions are not retaken later on when those same characters
> > > get read by TTY.
> > >
> > > Thus, pass lookahead count to receive_buf and skip
> > > flow-control character actions if already taken for the
> > > character in question. Lookahead count will become live after
> > > the next patch.
> >
> > ...
> >
> > > + if (c == STOP_CHAR(tty)) {
> > > + if (!lookahead_done)
> >
> > But now it can be as below
> >
> > if (c == STOP_CHAR(tty) && !lookahead_done)
> >
> > > + stop_tty(tty);
> > > + } else if ((c == START_CHAR(tty) && !lookahead_done) ||
> > > (tty->flow.stopped && !tty->flow.tco_stopped && I_IXANY(tty) &&
> > > c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) &&
> > > c != SUSP_CHAR(tty))) {
>
> Are you sure about this? ...If I make that change to the first if, the
> second part of the else if's condition get a chance it didn't have
> previously.
>
> What I'd like to do here is to take advantage of the function that was
> added:
>
> if (!n_tty_receive_char_flow_ctrl(tty, c) &&
Correcting myself.
if (!n_tty_receive_char_flow_ctrl(tty, c, lookahead_done) &&
is the correct form as this is already 2/3, not 1/3 form of that
function.
> tty->flow.stopped && !tty->flow.tco_stopped && I_IXANY(tty) &&
> c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) &&
> c != SUSP_CHAR(tty))) {
> start_tty(tty);
> process_echoes(tty);
> }
> ...but it will change STOP_CHAR vs START_CHAR precedence for the case
> where they're the same characters. I don't know if it matters.
>
>
--
i.
