Messages in this thread | | | Subject | Re: How to avoid serial port buffer overruns? | From | Lee Revell <> | Date | Wed, 16 Aug 2006 19:28:19 -0400 |
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On Thu, 2006-08-17 at 00:19 +0100, Russell King wrote: > On Wed, Aug 16, 2006 at 07:15:06PM -0400, Lee Revell wrote: > > On Thu, 2006-08-17 at 00:10 +0100, Russell King wrote: > > > MIDI uses its own driver - sound/drivers/serial-u16550.c. My guess > > > is there's something in the system starving interrupt servicing. > > > Serial is very sensitive to that, and increases in other system > > > latencies tends to have an adverse impact on serial. > > > > Have you seen many other reports of serial working reliably in 2.4 but > > not in 2.6? Right now this is the only clue I have to go on... > > There have been one or two, but the above is basically as far as I've > got. Unfortunately, I don't have any machines slow enough (or maybe > with the right hardware) to exhibit the problem. >
OK, thanks. FWIW here is the serial board we are using:
http://www.moschip.com/html/MCS9845.html
The hardware guy says "The mn9845cv, have in default 2 serial ports and one ISA bus, where we have connected the tl16c554, quad serial port."
Hopefully Ingo's latency tracer can tell me what is holding off interrupts.
Lee
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