Re: [PATCH] serial: revert "Use block_til_ready helper"

[Alan Cox]

> The way that the output is garbled seems to be just missing characters,
> in a mostly reproducible way. Repeatedly writing the string
> abcdefghijklmnopqrstuvwxyz1234567890 into ttyS0 gives an output like
> 'akq7m3iy', where only every sixteenth character is shown, plus
> an extra character in the second position.

Ok this sort of makes sense. Something isn't getting initialised and both
getty and minicom will do a termios set which is sorting it out.


And this is occurring because the generic block_til_ready sets
ASYNCB_NORMAL_ACTIVE so the termios updating gets skipped.

Ok the quickfix for this kernel is to delete this

       /*
         * If this is the first open to succeed, adjust things to suit.
         */
        if (retval == 0 && !(port->flags & ASYNC_NORMAL_ACTIVE)) {
                set_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);

                uart_update_termios(state);
        }

and paste it into

void tty_port_raise_dtr_rts(struct tty_port *port)
{
        if (port->ops->dtr_rts)
                port->ops->dtr_rts(port, 1);

		-->> HERE <<--
}


(the mutex is held by the caller)

That should cure it and then we can think about doing it more elegantly
by getting the serial layer to use tty_port_open, kfifo and the like and
removing the tons of repeated crap in all the drivers.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/