Re: [patch] irqchip/dw-apb-ictl: Fix generic domain chip wreckage

From: Thomas Gleixner
Date: Mon Jul 06 2015 - 09:24:32 EST


On Mon, 6 Jul 2015, Jisheng Zhang wrote:
> On Mon, 6 Jul 2015 14:55:43 +0200
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> > On Mon, 6 Jul 2015, Thomas Gleixner wrote:
> > > On Mon, 6 Jul 2015, Jisheng Zhang wrote:
> > > > > Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > > > the following patch seems fix the panic, but I dunno whether it's correct or not,
> > > > could you please help to check?
> > > >
> > > > Thanks,
> > > > Jisheng
> > > >
> > > > diff --git a/drivers/irqchip/irq-dw-apb-ictl.c b/drivers/irqchip/irq-dw-apb-ictl.c
> > > > index f4a0e11..8d996cb 100644
> > > > --- a/drivers/irqchip/irq-dw-apb-ictl.c
> > > > +++ b/drivers/irqchip/irq-dw-apb-ictl.c
> > > > @@ -30,13 +30,14 @@
> > > > static void dw_apb_ictl_handler(unsigned int irq, struct irq_desc *desc)
> > > > {
> > > > struct irq_domain *d = irq_desc_get_handler_data(desc);
> > > > - struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, 0);
> > > > + struct irq_chip_generic *gc;
> > > > struct irq_chip *chip = irq_desc_get_chip(desc);
> > > > int n;
> > > >
> > > > chained_irq_enter(chip, desc);
> > > >
> > > > - for (n = 0; n < d->gc->num_chips; n++, gc++) {
> > > > + for (n = 0; n < d->gc->num_chips; n++) {
> > > > + gc = irq_get_domain_generic_chip(d, n * 32);
> > > > u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
> > >
> > > Yes it's correct. Seems I tried to be overly clever by avoiding the
> > > lookup of the second chip. Will fold back.
> >
> > Hmm. That does not make sense because the real issue is here:
> >
> > - for (i = 0; i < nrirqs / 32; i++) {
> > + for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) {
> >
>
> OOPS, we need the above DIV_ROUND_UP fix. But...
>
> On Berlin SoC, nrirqs = 64, so it doesn't make difference and we get the same
> panic.

Yes, that's right. irq_domain_chip_generic->gc is an array of
pointers, not an array of generic chips. Stupid me...

Thanks,

tglx
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