x86, apic: Clear APIC Timer Initial Count Register on shutdown
authorAndreas Herrmann <herrmann.der.user@googlemail.com>
Tue, 27 Oct 2009 10:01:38 +0000 (11:01 +0100)
committerIngo Molnar <mingo@elte.hu>
Tue, 27 Oct 2009 13:54:21 +0000 (14:54 +0100)
commit6f9b41006af1bc489030f84ee247abc0df1edccd
tree94bbecb0774d1a82dfb87b3db64c876e4693bf0d
parentf88f2b4fdb1e098433ad2b005b6f7353f7268ce1
x86, apic: Clear APIC Timer Initial Count Register on shutdown

Commit a98f8fd24fb24fcb9a359553e64dd6aac5cf4279 (x86: apic reset
counter on shutdown) set the counter to max to avoid spurious
interrupts when the timer is re-enabled.

(In theory) you'll still get a spurious interrupt if spending
more than 344 seconds with this interrupt disabled and then
unmasking it.

The right thing to do is to clear the register. This disables
the interrupt from happening (at least it does on AMD hardware).

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20091027100138.GB30802@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/apic/apic.c