Subject: Re: How to avoid serial port buffer overruns?
From: Lee Revell <rlrevell@joe-job.com>
To: Russell King <rmk+lkml@arm.linux.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>, Raphael Hertzog <hertzog@debian.org>,
       Linux Kernel ML <linux-kernel@vger.kernel.org>
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Date: Wed, 16 Aug 2006 19:15:06 -0400
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On Thu, 2006-08-17 at 00:10 +0100, Russell King wrote:
> On Wed, Aug 16, 2006 at 05:24:26PM -0500, Paul Fulghum wrote:
> > Does the MIDI device using the standard N_TTY line discipline?
> > Are you using the low_latency flag on the serial device?
> > What type of UART has been tested (16550? other?)
> > Are you seeing overruns or just lost data?
> 
> 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.
> 

Thanks.

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...

Lee

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