Re: PATCH 2.4.0.10.3: pc_keyb and q40_keyb cleanup

From: Andrea Arcangeli (andrea@suse.de)
Date: Tue Oct 17 2000 - 11:37:13 EST


On Tue, Oct 17, 2000 at 05:43:34PM +0200, Jes Sorensen wrote:
> Which shouldn't matter as the irq source should be disabled. In fact I
> thought we were guaranteed not to be re-interrupted in a handler
> unless one explicitly does __sti(), has this changed?

A single irq handler won't be re-interrupted, correct. Not even if you do
__sti().

(in the edge triggered IO-APIC case, the irq source is not disabled to avoid
missing events but the highlevel irq logic makes sure that the irq _handler_
won't be run if it was just in-progress somewhere in the system, even
if in another CPU)

But the fact the irq handler is single threaded with respect to itself is
irrelevant with the keyboard_interrupt case because that irq handler will be
recalled by _two_ indipendent irq lines (irq 2 for the keyboard and irq 12 for
the PS/2 Mouse).

Andrea
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