[PATCH 0/2] [RFC] RT: Optionally allow IRQF_NODELAY on serial console

From: Gregory Haskins
Date: Fri Oct 05 2007 - 11:44:33 EST


This series may help debugging certain circumstances where the serial
console is unreponsive (e.g. RT51+ spinner, or scheduler problem). It changes
the serial8250 driver to use IRQF_NODELAY so that interrupts execute in irq
context instead of a kthread.

It works pretty well on this end, though it is admitted not fully baked. For
instance, a few paths in sysrq can still call into non-raw spinlocks
(sched_debug_show, for instance) which will cause subsequent errors. Also,
if you use KDB, be sure to convert the kdb_printf_lock to raw as well. I may
send a KDB related patch seperately.

I am sending this out now in case it is helpful to someone.

Regards,
-Greg
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