diff options
Diffstat (limited to 'sys/dev/sio/sio.c')
| -rw-r--r-- | sys/dev/sio/sio.c | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/sys/dev/sio/sio.c b/sys/dev/sio/sio.c index 5cc1f6c..d4125c3 100644 --- a/sys/dev/sio/sio.c +++ b/sys/dev/sio/sio.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * from: @(#)com.c 7.5 (Berkeley) 5/16/91 - * $Id: sio.c,v 1.150 1996/11/30 14:51:04 bde Exp $ + * $Id: sio.c,v 1.151 1996/11/30 15:03:05 bde Exp $ */ #include "opt_comconsole.h" @@ -285,6 +285,7 @@ static int espattach __P((struct isa_device *isdp, struct com_s *com, Port_t esp_port)); #endif static int sioattach __P((struct isa_device *dev)); +static timeout_t siobusycheck; static timeout_t siodtrwakeup; static void comhardclose __P((struct com_s *com)); static void siointr1 __P((struct com_s *com)); @@ -1274,6 +1275,35 @@ siowrite(dev, uio, flag) } static void +siobusycheck(chan) + void *chan; +{ + struct com_s *com; + int s; + + com = (struct com_s *)chan; + + /* + * Clear TS_BUSY if low-level output is complete. + * spl locking is sufficient because siointr1() does not set CS_BUSY. + * If siointr() clears CS_BUSY after we look at it, then we'll get + * called again. Reading the line status port outside of siointr1() + * is safe because CS_BUSY is clear so there are no output interrupts + * to lose. + */ + s = spltty(); + if (com->state & CS_BUSY) + ; /* False alarm. */ + else if ((inb(com->line_status_port) & (LSR_TSRE | LSR_TXRDY)) + == (LSR_TSRE | LSR_TXRDY)) { + com->tp->t_state &= ~TS_BUSY; + ttwwakeup(com->tp); + } else + timeout(siobusycheck, com, hz / 100); + splx(s); +} + +static void siodtrwakeup(chan) void *chan; { @@ -1753,9 +1783,9 @@ repeat: disable_intr(); com_events -= LOTS_OF_EVENTS; com->state &= ~CS_ODONE; - if (!(com->state & CS_BUSY)) - com->tp->t_state &= ~TS_BUSY; enable_intr(); + if (!(com->state & CS_BUSY)) + timeout(siobusycheck, com, hz / 100); (*linesw[tp->t_line].l_start)(tp); } if (incc <= 0 || !(tp->t_state & TS_ISOPEN) || |
