svn commit: r294362 - in head/sys: dev/uart kern sys
Marius Strobl
marius at FreeBSD.org
Tue Jan 19 23:34:29 UTC 2016
Author: marius
Date: Tue Jan 19 23:34:27 2016
New Revision: 294362
URL: https://svnweb.freebsd.org/changeset/base/294362
Log:
Fix tty_drain() and, thus, TIOCDRAIN of the current tty(4) incarnation
to actually wait until the TX FIFOs of UARTs have be drained before
returning. This is done by bringing the equivalent of the TS_BUSY flag
found in the previous implementation back in an ABI-preserving way.
Reported and tested by: Patrick Powell
Most likely, drivers for USB-serial-adapters likewise incorporating
TX FIFOs as well as other terminal devices that buffer output in some
form should also provide implementations of tsw_busy.
MFC after: 3 days
Modified:
head/sys/dev/uart/uart_tty.c
head/sys/kern/tty.c
head/sys/sys/ttydevsw.h
Modified: head/sys/dev/uart/uart_tty.c
==============================================================================
--- head/sys/dev/uart/uart_tty.c Tue Jan 19 23:28:18 2016 (r294361)
+++ head/sys/dev/uart/uart_tty.c Tue Jan 19 23:34:27 2016 (r294362)
@@ -355,6 +355,18 @@ uart_tty_free(void *arg)
*/
}
+static bool
+uart_tty_busy(struct tty *tp)
+{
+ struct uart_softc *sc;
+
+ sc = tty_softc(tp);
+ if (sc == NULL || sc->sc_leaving)
+ return (FALSE);
+
+ return (sc->sc_txbusy);
+}
+
static struct ttydevsw uart_tty_class = {
.tsw_flags = TF_INITLOCK|TF_CALLOUT,
.tsw_open = uart_tty_open,
@@ -365,6 +377,7 @@ static struct ttydevsw uart_tty_class =
.tsw_param = uart_tty_param,
.tsw_modem = uart_tty_modem,
.tsw_free = uart_tty_free,
+ .tsw_busy = uart_tty_busy,
};
int
Modified: head/sys/kern/tty.c
==============================================================================
--- head/sys/kern/tty.c Tue Jan 19 23:28:18 2016 (r294361)
+++ head/sys/kern/tty.c Tue Jan 19 23:34:27 2016 (r294362)
@@ -132,11 +132,11 @@ tty_drain(struct tty *tp, int leaving)
/* buffer is inaccessible */
return (0);
- while (ttyoutq_bytesused(&tp->t_outq) > 0) {
+ while (ttyoutq_bytesused(&tp->t_outq) > 0 || ttydevsw_busy(tp)) {
ttydevsw_outwakeup(tp);
/* Could be handled synchronously. */
bytesused = ttyoutq_bytesused(&tp->t_outq);
- if (bytesused == 0)
+ if (bytesused == 0 && !ttydevsw_busy(tp))
return (0);
/* Wait for data to be drained. */
@@ -955,6 +955,13 @@ ttydevsw_deffree(void *softc)
panic("Terminal device freed without a free-handler");
}
+static bool
+ttydevsw_defbusy(struct tty *tp __unused)
+{
+
+ return (FALSE);
+}
+
/*
* TTY allocation and deallocation. TTY devices can be deallocated when
* the driver doesn't use it anymore, when the TTY isn't a session's
@@ -989,6 +996,7 @@ tty_alloc_mutex(struct ttydevsw *tsw, vo
PATCH_FUNC(mmap);
PATCH_FUNC(pktnotify);
PATCH_FUNC(free);
+ PATCH_FUNC(busy);
#undef PATCH_FUNC
tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
Modified: head/sys/sys/ttydevsw.h
==============================================================================
--- head/sys/sys/ttydevsw.h Tue Jan 19 23:28:18 2016 (r294361)
+++ head/sys/sys/ttydevsw.h Tue Jan 19 23:34:27 2016 (r294362)
@@ -54,6 +54,7 @@ typedef int tsw_mmap_t(struct tty *tp, v
vm_paddr_t * paddr, int nprot, vm_memattr_t *memattr);
typedef void tsw_pktnotify_t(struct tty *tp, char event);
typedef void tsw_free_t(void *softc);
+typedef bool tsw_busy_t(struct tty *tp);
struct ttydevsw {
unsigned int tsw_flags; /* Default TTY flags. */
@@ -74,7 +75,9 @@ struct ttydevsw {
tsw_free_t *tsw_free; /* Destructor. */
- void *tsw_spare[4]; /* For future use. */
+ tsw_busy_t *tsw_busy; /* Draining output. */
+
+ void *tsw_spare[3]; /* For future use. */
};
static __inline int
@@ -181,4 +184,13 @@ ttydevsw_free(struct tty *tp)
tp->t_devsw->tsw_free(tty_softc(tp));
}
+static __inline bool
+ttydevsw_busy(struct tty *tp)
+{
+
+ MPASS(tty_gone(tp));
+
+ return (tp->t_devsw->tsw_busy(tp));
+}
+
#endif /* !_SYS_TTYDEVSW_H_ */
More information about the svn-src-head
mailing list