src/sys/dev/uart/uart_dev_ns8250.c, branch releng/6.2

MFS: Remove 16-bit wide I/O. It breaks when the register shift

2006-11-29T17:54:59+00:00

is non-null and may not work on all chipsets.

PR: i386/105616
Approved by: re (kensmith)

Start each of the license/copyright comments with /*-, minor shuffle of lines

2005-01-06T01:43:34+00:00

Include the common instead of the private

2004-11-20T23:22:04+00:00

. The latter can be removed now.

Be slightly more paranoid about using the divisor in a division and

2004-11-15T00:00:24+00:00

the calculated baudrate. Neither should be 0.

Implement UART_IOCTL_BAUD. Consequently, when the baudrate was unset

2004-11-14T23:31:19+00:00

for the console, we emit the actual baudrate during bus enumeration.

Do not use hardware flow control for the moment. There are some issues

2004-08-06T15:51:31+00:00

with it that need to be understood better before they can be resolved.
This takes time and time is already in short supply.

Reported & tested by: glebius@

When sizing the FIFO, don't count all the way up to 1030 if any FIFO

2004-07-26T03:54:40+00:00

size larger than 128 is considered an incompatible size. Stop counting
when we reach 130 in the loop.

Use the new serial port definitions for modemsignals.

2004-06-24T10:07:28+00:00

It seems that clearing the MCR_IE bit in the modem control register

2004-05-26T21:59:01+00:00

does not reliably prevent the triggering of interrupts for all supported
configurations. Thus, the FIFO size probe could cause an interrupt,
which could lead to an interrupt storm in the shared interrupt case.

To prevent this, change ns8250_bus_probe() to use the overflow bit in
the line status register instead of the RX ready bit in the interrupt
identification register to detect whether the FIFO has filled up.
This allows us to clear all bits in the interrupt enable register during
the probe, which should prevent interrupts reliably.
Additionally, the detected FIFO size may be a bit more accurate, because
the overflow bit is only set when the FIFO did actually fill up, while
interrupts would trigger a bit early.

Reviewed and tested on a lot of hardware by:	marcel

In ns8250_putc() insert a barrier between writing the character and

2004-04-02T07:37:28+00:00

checking for transmitter empty.