From: Andreas Herrmann Date: Tue, 27 Oct 2009 10:01:38 +0000 (+0100) Subject: x86, apic: Clear APIC Timer Initial Count Register on shutdown X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6f9b41006af1bc489030f84ee247abc0df1edccd;p=linux-beck.git 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 LKML-Reference: <20091027100138.GB30802@alberich.amd.com> Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index dce93d4b0eaf..4c689f45b238 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -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 */