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Re: [Qemu-devel] [PATCH v5 1/5] hpet: inverse polarity when pin above IS
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v5 1/5] hpet: inverse polarity when pin above ISA_NUM_IRQS |
Date: |
Sat, 28 Sep 2013 22:52:13 +0300 |
On Thu, Sep 12, 2013 at 11:25:14AM +0800, Liu Ping Fan wrote:
> According to hpet spec, hpet irq is high active. But according to
> ICH spec, there is inversion before the input of ioapic. So the OS
> will expect low active on this IRQ line.
>(And this is observed on
> bare metal).
How does one test this on bare metal?
>
> We fold the emulation of this inversion inside the hpet logic.
>
> Signed-off-by: Liu Ping Fan <address@hidden>
Doesn't this affect cross-version migration?
E.g. imagine that you migrate between systems
with/without this fix.
> ---
> hw/timer/hpet.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c
> index fcd22ae..8429eb3 100644
> --- a/hw/timer/hpet.c
> +++ b/hw/timer/hpet.c
> @@ -198,13 +198,23 @@ static void update_irq(struct HPETTimer *timer, int set)
> if (!set || !timer_enabled(timer) || !hpet_enabled(timer->state)) {
> s->isr &= ~mask;
> if (!timer_fsb_route(timer)) {
> - qemu_irq_lower(s->irqs[route]);
> + /* fold the ICH PIRQ# pin's internal inversion logic into hpet */
> + if (route >= ISA_NUM_IRQS) {
> + qemu_irq_raise(s->irqs[route]);
> + } else {
> + qemu_irq_lower(s->irqs[route]);
> + }
> }
> } else if (timer_fsb_route(timer)) {
> stl_le_phys(timer->fsb >> 32, timer->fsb & 0xffffffff);
> } else if (timer->config & HPET_TN_TYPE_LEVEL) {
> s->isr |= mask;
> - qemu_irq_raise(s->irqs[route]);
> + /* fold the ICH PIRQ# pin's internal inversion logic into hpet */
> + if (route >= ISA_NUM_IRQS) {
> + qemu_irq_lower(s->irqs[route]);
> + } else {
> + qemu_irq_raise(s->irqs[route]);
> + }
> } else {
> s->isr &= ~mask;
> qemu_irq_pulse(s->irqs[route]);
> --
> 1.8.1.4
>
[Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, Liu Ping Fan, 2013/09/11
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, Michael S. Tsirkin, 2013/09/28
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, liu ping fan, 2013/09/28
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, Michael S. Tsirkin, 2013/09/29
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, liu ping fan, 2013/09/30
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, Michael S. Tsirkin, 2013/09/30
- Re: [Qemu-devel] [PATCH v5 2/5] hpet: entitle more irq pins for hpet, Paolo Bonzini, 2013/09/30