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* [PATCH] KVM: PIT: support mode 3
@ 2008-05-02 15:02 Aurelien Jarno
  2008-05-04 13:27 ` Avi Kivity
  0 siblings, 1 reply; 2+ messages in thread
From: Aurelien Jarno @ 2008-05-02 15:02 UTC (permalink / raw)
  To: Avi Kivity; +Cc: kvm-devel

The in-kernel PIT emulation ignores pending timers if operating
under mode 3, which for example Hurd uses.

This mode should output a square wave, high for (N+1)/2 counts and low
for (N-1)/2 counts. As we only care about the resulting interrupts, the
period is N, and mode 3 is the same as mode 2 with regard to 
interrupts.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
---
 arch/x86/kvm/i8254.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 1646102..61cc450 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -293,6 +293,7 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
 		create_pit_timer(&ps->pit_timer, val, 0);
 		break;
 	case 2:
+	case 3:
 		create_pit_timer(&ps->pit_timer, val, 1);
 		break;
 	default:
-- 
1.5.5

-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32@debian.org         | aurelien@aurel32.net
   `-    people.debian.org/~aurel32 | www.aurel32.net

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^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] KVM: PIT: support mode 3
  2008-05-02 15:02 [PATCH] KVM: PIT: support mode 3 Aurelien Jarno
@ 2008-05-04 13:27 ` Avi Kivity
  0 siblings, 0 replies; 2+ messages in thread
From: Avi Kivity @ 2008-05-04 13:27 UTC (permalink / raw)
  To: Aurelien Jarno; +Cc: kvm-devel

Aurelien Jarno wrote:
> The in-kernel PIT emulation ignores pending timers if operating
> under mode 3, which for example Hurd uses.
>
> This mode should output a square wave, high for (N+1)/2 counts and low
> for (N-1)/2 counts. As we only care about the resulting interrupts, the
> period is N, and mode 3 is the same as mode 2 with regard to 
> interrupts.
>
>   

Applied, thanks.

-- 
error compiling committee.c: too many arguments to function


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^ permalink raw reply	[flat|nested] 2+ messages in thread

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