On Fri, Feb 07, 2025 at 06:35:04AM +0100, Emile `iMil' Heitor wrote:
> On Wed, 5 Feb 2025, Emile `iMil' Heitor wrote:
>
> > After several back-and-forths, thanks Martin, Simon and Taylor for
> > your help, here's a cleaner approach based on prop_dictionary_util,
> > avoiding #ifdefs:
>
> Another day, another proposal!
> Here are the results of discussions about finally getting rid of delay()
> and instead checking LSR_TXRDY (aka LSR_THRE) or LSR_TSRE (aka LSR_TEMT)
>
> diff --git a/sys/dev/ic/com.c b/sys/dev/ic/com.c
> index d271b594346..082b5b8a985 100644
> --- a/sys/dev/ic/com.c
> +++ b/sys/dev/ic/com.c
> @@ -536,6 +536,7 @@ com_attach_subr(struct com_softc *sc)
> struct tty *tp;
> uint32_t cpr;
> uint8_t lcr;
> + int timo;
> const char *fifo_msg = NULL;
> prop_dictionary_t dict;
> bool is_console = true;
> @@ -588,9 +589,13 @@ com_attach_subr(struct com_softc *sc)
> sc->sc_lcr = cflag2lcr(comcons_info.cflag);
> break;
> }
> + /* wait for output to finish */
> + timo = 10000;
> + while (!ISSET(CSR_READ_1(regsp, COM_REG_LSR),
> + LSR_TXRDY | LSR_TSRE) && --timo)
> + continue;
>
> /* Make sure the console is always "hardwired". */
> - delay(10000); /* wait for output to finish
> */
> if (is_console) {
> SET(sc->sc_hwflags, COM_HW_CONSOLE);
> }
timo looks way too low to me.
On a multi-gHz CPU, counting from 10000 to 0 doens't even let you send
one byte at 9600bds.
Another way to compute the timeout is probably needed.
--
Manuel Bouyer <bou...@antioche.eu.org>
NetBSD: 26 ans d'experience feront toujours la difference
--
