Re: How to avoid serial port buffer overruns?

From: Russell King
Date: Wed Aug 16 2006 - 19:08:08 EST

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.

Russell King
Linux kernel 2.6 ARM Linux -
maintainer of: 2.6 Serial core
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