Re: [PATCH] x86: Get irq for hpet timer

From: Kevin Hao
Date: Fri May 16 2008 - 04:07:36 EST


On Fri, 2008-05-16 at 13:23 +0530, Balaji Rao R wrote:
> On Fri, May 16, 2008 at 11:35 AM, Kevin Hao <kexin.hao@xxxxxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > x86: get irq for hpet timer
> >
> > HPET timer's IRQ is 0 by default, so we have to select which irq
> > will be used for these timers. We wait to set the timer's irq until
> > we really turn on interrupt in order to reduce the chance of
> > conflicting with some legacy device.
> >
> Yes, this is alright. But i've seen some machines where we have a
> valid IRQ in 'devp->hd_hdwirq' which you should not ignore. So, first
> check if it is zero and only then do a hpet_timer_get_irq.

Yes, I have checked that case in hpet_timer_get_irq function. See the
following code:

+ irq = devp->hd_hdwirq;


+ if (irq) {
+ if (request_irq(irq, hpet_interrupt, irq_flags,
+ devp->hd_name, (void *)devp)) {
+ printk(KERN_ERR "hpet: IRQ %d is not free\n",
irq);
+ irq = 0;
+ }
+ return irq;
+ }

Is that right?

Thanks for your comments.

Best Regards,
Kevin

>
> --
> warm regards
>
> Balaji Rao
> NITK Surathkal
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