On Wed, 4 Sep 2002, Stuart MacDonald wrote:

From: <redacted>

quoted

Hm... Hardware problem on different chipsets, different processors,
different kernels(only chip is 16550A). I understand, that this can
indicate hardware problems.

That certainly indicates a driver problem. Interesting.

quoted

OK, I know that. It is clear. Can You tell me, why usleep(100) totally
eliminates the problem with garbage?

No idea, except that you're getting lucky. Always start the receiver
first.

:) Starting sender, starting receiver, CtrlC (kill -15, getting KILL
signal in the prog). One note: both ports are on the same comp.

quoted

when often open/close/startprog with serial ports. For example, running
script, that launches the prog and killing it, can kill the comp in a
short period of time with overruns.

Double check that you don't have any irq conflicts.

Quatro check. I do not know how, but serverworks defines IRQs after 16 for
side devices. But I have pure computers, without any devices. Of cource,
I've got bad results on well-weaponed comp (audio, video IO etc.).
With another chipset (860). Then, checkin new computers, that are virgin.

An overrun can
happen when the driver's handler is delayed too long.

I see this, in the driver. But do not know what to do.

It used to be
that the IDE interrupt handler was very long, and that would delay
other handlers, including the serial driver's.

Ah! Those old discussion about slow(long) and fast(short) interrupts?

Also, double check that
the resources (irq, memory, etc) you're using for the ISA slots is
reserved by the bios so that the PCI system doesn't also use it.

Hm... Where riside COM on-board ports? On which BUS (PCI/ISA)?

Hm, actually, I've assumed that you have serial ports on an ISA card.
T'so, although he hasn't done much with it recently), or perhaps
Russell King (likely the next serial maintainer). I'm just a serial
driver hacker. :-)

:-)
OK.

interrupt routine is being delayed. There is a low latency patch (or
possibly config option) that speeds up the handling of bytes in the
serial/tty drivers; you could try that and see if it helps.

Thanx!