Differential D47073 Diff 144857 sys/dev/uart/uart_dev_ns8250.c

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sys/dev/uart/uart_dev_ns8250.c

Show First 20 Lines • Show All 181 Lines • ▼ Show 20 Lines	if (what & UART_DRAIN_TRANSMITTER) {
* Pick an arbitrary high limit to avoid getting stuck in		* Pick an arbitrary high limit to avoid getting stuck in
* an infinite loop when the hardware is broken. Make the		* an infinite loop when the hardware is broken. Make the
* limit high enough to handle large FIFOs.		* limit high enough to handle large FIFOs.
*/		*/
limit = 10*1024;		limit = 10*1024;
while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit)		while ((uart_getreg(bas, REG_LSR) & LSR_TEMT) == 0 && --limit)
DELAY(delay);		DELAY(delay);
if (limit == 0) {		if (limit == 0) {
/* printf("ns8250: transmitter appears stuck... "); */		/* printf("uart: ns8250: transmitter appears stuck... "); */
return (EIO);		return (EIO);
}		}
}		}

if (what & UART_DRAIN_RECEIVER) {		if (what & UART_DRAIN_RECEIVER) {
/*		/*
* Pick an arbitrary high limit to avoid getting stuck in		* Pick an arbitrary high limit to avoid getting stuck in
* an infinite loop when the hardware is broken. Make the		* an infinite loop when the hardware is broken. Make the
Show All 11 Lines	while (limit && (uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit) {
do {		do {
(void)uart_getreg(bas, REG_DATA);		(void)uart_getreg(bas, REG_DATA);
uart_barrier(bas);		uart_barrier(bas);
} while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit);		} while ((uart_getreg(bas, REG_LSR) & LSR_RXRDY) && --limit);
uart_barrier(bas);		uart_barrier(bas);
DELAY(delay << 2);		DELAY(delay << 2);
}		}
if (limit == 0) {		if (limit == 0) {
/* printf("ns8250: receiver appears broken... "); */		/* printf("uart: ns8250: receiver appears broken... "); */
return (EIO);		return (EIO);
}		}
}		}

return (0);		return (0);
}		}

/*		/*
Show All 23 Lines	ns8250_flush(struct uart_bas *bas, int what)
* https://github.com/rust-vmm/vm-superio/issues/83		* https://github.com/rust-vmm/vm-superio/issues/83
*/		*/
lsr = uart_getreg(bas, REG_LSR);		lsr = uart_getreg(bas, REG_LSR);
if (((lsr & LSR_TEMT) == 0) && (what & UART_FLUSH_TRANSMITTER))		if (((lsr & LSR_TEMT) == 0) && (what & UART_FLUSH_TRANSMITTER))
drain \|= UART_DRAIN_TRANSMITTER;		drain \|= UART_DRAIN_TRANSMITTER;
if ((lsr & LSR_RXRDY) && (what & UART_FLUSH_RECEIVER))		if ((lsr & LSR_RXRDY) && (what & UART_FLUSH_RECEIVER))
drain \|= UART_DRAIN_RECEIVER;		drain \|= UART_DRAIN_RECEIVER;
if (drain != 0) {		if (drain != 0) {
printf("ns8250: UART FCR is broken\n");		printf("uart: ns8250: UART FCR is broken\n");
ns8250_drain(bas, drain);		ns8250_drain(bas, drain);
}		}
}		}

static int		static int
ns8250_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,		ns8250_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
int parity)		int parity)
{		{
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