diff options
| author | marcel <marcel@FreeBSD.org> | 2006-04-01 19:04:54 +0000 |
|---|---|---|
| committer | marcel <marcel@FreeBSD.org> | 2006-04-01 19:04:54 +0000 |
| commit | 01ed5990aef062b97e91680895804b9689c8076b (patch) | |
| tree | f866ed454b38b3e3ed100d7237faffef820e51f3 /sys/dev/uart/uart_dev_ns8250.c | |
| parent | 6d14bcd43fdc1e895dd4255bb9f88dba939296ce (diff) | |
| download | FreeBSD-src-01ed5990aef062b97e91680895804b9689c8076b.zip FreeBSD-src-01ed5990aef062b97e91680895804b9689c8076b.tar.gz | |
Don't hold the hardware mutex across getc(). It can wait indefinitely
for a character to be received. Instead let getc() do any necesary
locking.
Diffstat (limited to 'sys/dev/uart/uart_dev_ns8250.c')
| -rw-r--r-- | sys/dev/uart/uart_dev_ns8250.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/sys/dev/uart/uart_dev_ns8250.c b/sys/dev/uart/uart_dev_ns8250.c index 378639f..adb4502 100644 --- a/sys/dev/uart/uart_dev_ns8250.c +++ b/sys/dev/uart/uart_dev_ns8250.c @@ -217,7 +217,7 @@ static void ns8250_init(struct uart_bas *bas, int, int, int, int); static void ns8250_term(struct uart_bas *bas); static void ns8250_putc(struct uart_bas *bas, int); static int ns8250_poll(struct uart_bas *bas); -static int ns8250_getc(struct uart_bas *bas); +static int ns8250_getc(struct uart_bas *bas, struct mtx *); struct uart_ops uart_ns8250_ops = { .probe = ns8250_probe, @@ -321,16 +321,26 @@ ns8250_poll(struct uart_bas *bas) } static int -ns8250_getc(struct uart_bas *bas) +ns8250_getc(struct uart_bas *bas, struct mtx *hwmtx) { - int delay; + int c, delay; + + uart_lock(hwmtx); /* 1/10th the time to transmit 1 character (estimate). */ delay = ns8250_delay(bas); - while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) == 0) + while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) == 0) { + uart_unlock(hwmtx); DELAY(delay); - return (uart_getreg(bas, REG_DATA)); + uart_lock(hwmtx); + } + + c = uart_getreg(bas, REG_DATA); + + uart_unlock(hwmtx); + + return (c); } /* |
