O2 serial flow control

[Mark Hughes]

I have a serial printer on an O2 /dev/ttyd2 port. The printer sends
XOFF but
the O2 doesn't stop sending for a few seconds (100+ characters). Is
there a patch
or some way to tweak the driver?

[Walter Roberson]

In article <37EBF562...@cyberware.com>,
Mark Hughes <ma...@cyberware.com> wrote:
:I have a serial printer on an O2 /dev/ttyd2 port. The printer sends

Try reducing the DUART reservation time in /var/sysgen/master.d/sduart
and rebuilding your kernel and rebooting.

[Richard Masoner]

In article <7sh3ll$3ki$1...@canopus.cc.umanitoba.ca>,

robe...@ibd.nrc.ca (Walter Roberson) writes:
> In article <37EBF562...@cyberware.com>,
> Mark Hughes <ma...@cyberware.com> wrote:

>:I have a serial printer on an O2 /dev/ttyd2 port. The printer sends
>:XOFF but the O2 doesn't stop sending for a few seconds (100+ characters).

> Try reducing the DUART reservation time in /var/sysgen/master.d/sduart

> and rebuilding your kernel and rebooting.

Would this work? From what I understand, this just reduces the amount
of buffering between the serial driver and the line discipline. I
would hope that flow control is handled in the device driver, rather
than in the line discipline.

Is duart_rsrv_duration in clock ticks, or seconds? If it's in seconds,
and if flow control is handled by the layer above sduart, then I can
see how this would help.

If Walter's suggestion doesn't work, Mr. Hughes should consider using
hardware flow control on his printer.

Richard Masoner