Re: Linux serial port dropping bytes

On 2008-04-01, Derek Young <edu.mit.LL@xxxxxxxxxxxxx> wrote:

Yes, I feel like there should be plenty of time to handle the
interrupts. But from what I understand (which isn't a whole
lot mind you :P), Linux isn't strictly a real-time OS. It
doesn't normally have a preemptible kernel (I've turned on the
"experimental" preemptible kernel flag) and it doesn't really
have a standard way to tweak interrupt priorities.

Was wondering if anybody knew of a straight-forward hack. I
just want the serial port ISR to get priority over the device
driver ISRs.

Changing ISR priority isn't going to make any difference.

It only determines which of two pending interrupts get
serviced. It doesn't allow "higher" priority interrupts to
preempt lower priority ones. If a low-priority ISR runs for a
long time, it's still going to block high-priority ISRs for the
whole time it's running.

--
Grant Edwards grante Yow! As President I have
at to go vacuum my coin
visi.com collection!
.

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