x86, apic: Clear APIC Timer Initial Count Register on shutdown

Commit a98f8fd24f (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>
This commit is contained in:
Andreas Herrmann 2009-10-27 11:01:38 +01:00 committed by Ingo Molnar
parent f88f2b4fdb
commit 6f9b41006a

View File

@ -444,7 +444,7 @@ static void lapic_timer_setup(enum clock_event_mode mode,
v = apic_read(APIC_LVTT);
v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
apic_write(APIC_LVTT, v);
apic_write(APIC_TMICT, 0xffffffff);
apic_write(APIC_TMICT, 0);
break;
case CLOCK_EVT_MODE_RESUME:
/* Nothing to do here */