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Fix RTS/CTS flow control, broken by the TTY overhaul. The new TTY

Browse source 
interface is fairly simple WRT dealing with flow control, but
needed 2 new RX buffer functions with "get-char-from-buf" separated
from "advance-buf-pointer" so that the pointer could be advanced
only when ttydisc_rint() succeeded.

MFC after:	1 week
This commit is contained in:
Marcel Moolenaar 2009-10-02 22:30:44 +00:00
parent afd8e45b45
commit 0acb3c4aac
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=197721
3 changed files with 55 additions and 27 deletions
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25
sys/dev/uart/uart_bus.h
View file

@ -96,6 +96,7 @@ struct uart_softc {
int sc_opened:1; /* This UART is open for business. */
int sc_polled:1; /* This UART has no interrupts. */
int sc_txbusy:1; /* This UART is transmitting. */
int sc_isquelch:1; /* This UART has input squelched. */
struct uart_devinfo *sc_sysdev; /* System device (or NULL). */
@ -141,6 +142,8 @@ int uart_bus_ipend(device_t dev);
int uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan);
int uart_bus_sysdev(device_t dev);
void uart_sched_softih(struct uart_softc *, uint32_t);
int uart_tty_attach(struct uart_softc *);
int uart_tty_detach(struct uart_softc *);
void uart_tty_intr(void *arg);
@ -174,6 +177,28 @@ uart_rx_get(struct uart_softc *sc)
return (xc);
}
static __inline int
uart_rx_next(struct uart_softc *sc)
{
int ptr;
ptr = sc->sc_rxget;
if (ptr == sc->sc_rxput)
return (-1);
ptr += 1;
sc->sc_rxget = (ptr < sc->sc_rxbufsz) ? ptr : 0;
return (0);
}
static __inline int
uart_rx_peek(struct uart_softc *sc)
{
int ptr;
ptr = sc->sc_rxget;
return ((ptr == sc->sc_rxput) ? -1 : sc->sc_rxbuf[ptr]);
}
static __inline int
uart_rx_put(struct uart_softc *sc, int xc)
{

2
sys/dev/uart/uart_core.c
View file

@ -91,7 +91,7 @@ uart_getrange(struct uart_class *uc)
* Schedule a soft interrupt. We do this on the 0 to !0 transition
* of the TTY pending interrupt status.
*/
static void
void
uart_sched_softih(struct uart_softc *sc, uint32_t ipend)
{
uint32_t new, old;

55
sys/dev/uart/uart_tty.c
View file

@ -166,27 +166,6 @@ uart_tty_outwakeup(struct tty *tp)
if (sc == NULL || sc->sc_leaving)
return;
/*
* Handle input flow control. Note that if we have hardware support,
* we don't do anything here. We continue to receive until our buffer
* is full. At that time we cannot empty the UART itself and it will
* de-assert RTS for us. In that situation we're completely stuffed.
* Without hardware support, we need to toggle RTS ourselves.
*/
if ((tp->t_termios.c_cflag & CRTS_IFLOW) && !sc->sc_hwiflow) {
#if 0
/*if ((tp->t_state & TS_TBLOCK) &&
(sc->sc_hwsig & SER_RTS))
UART_SETSIG(sc, SER_DRTS);
else */ if (/*!(tp->t_state & TS_TBLOCK) &&*/
!(sc->sc_hwsig & SER_RTS))
UART_SETSIG(sc, SER_DRTS|SER_RTS);
#endif
/* XXX: we should use inwakeup to implement this! */
if (!(sc->sc_hwsig & SER_RTS))
UART_SETSIG(sc, SER_DRTS|SER_RTS);
}
if (sc->sc_txbusy)
return;
@ -195,6 +174,23 @@ uart_tty_outwakeup(struct tty *tp)
UART_TRANSMIT(sc);
}
static void
uart_tty_inwakeup(struct tty *tp)
{
struct uart_softc *sc;
sc = tty_softc(tp);
if (sc == NULL || sc->sc_leaving)
return;
if (sc->sc_isquelch) {
if ((tp->t_termios.c_cflag & CRTS_IFLOW) && !sc->sc_hwiflow)
UART_SETSIG(sc, SER_DRTS|SER_RTS);
sc->sc_isquelch = 0;
uart_sched_softih(sc, SER_INT_RXREADY);
}
}
static int
uart_tty_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
@ -252,9 +248,9 @@ uart_tty_param(struct tty *tp, struct termios *t)
UART_SETSIG(sc, SER_DDTR | SER_DTR);
/* Set input flow control state. */
if (!sc->sc_hwiflow) {
/* if ((t->c_cflag & CRTS_IFLOW) && (tp->t_state & TS_TBLOCK))
if ((t->c_cflag & CRTS_IFLOW) && sc->sc_isquelch)
UART_SETSIG(sc, SER_DRTS);
else */
else
UART_SETSIG(sc, SER_DRTS | SER_RTS);
} else
UART_IOCTL(sc, UART_IOCTL_IFLOW, (t->c_cflag & CRTS_IFLOW));
@ -294,8 +290,8 @@ uart_tty_intr(void *arg)
tty_lock(tp);
if (pend & SER_INT_RXREADY) {
while (!uart_rx_empty(sc) /* && !(tp->t_state & TS_TBLOCK)*/) {
xc = uart_rx_get(sc);
while (!uart_rx_empty(sc) && !sc->sc_isquelch) {
xc = uart_rx_peek(sc);
c = xc & 0xff;
if (xc & UART_STAT_FRAMERR)
err |= TRE_FRAMING;
@ -303,7 +299,13 @@ uart_tty_intr(void *arg)
err |= TRE_OVERRUN;
if (xc & UART_STAT_PARERR)
err |= TRE_PARITY;
ttydisc_rint(tp, c, err);
if (ttydisc_rint(tp, c, err) != 0) {
sc->sc_isquelch = 1;
if ((tp->t_termios.c_cflag & CRTS_IFLOW) &&
!sc->sc_hwiflow)
UART_SETSIG(sc, SER_DRTS);
} else
uart_rx_next(sc);
}
}
@ -344,6 +346,7 @@ static struct ttydevsw uart_tty_class = {
.tsw_open = uart_tty_open,
.tsw_close = uart_tty_close,
.tsw_outwakeup = uart_tty_outwakeup,
.tsw_inwakeup = uart_tty_inwakeup,
.tsw_ioctl = uart_tty_ioctl,
.tsw_param = uart_tty_param,
.tsw_modem = uart_tty_modem,