On Thu, Mar 31, 2016 at 5:09 PM, Maxime Coquelin
<mcoquelin.stm32@xxxxxxxxx> wrote:
> +static void stm32_irq_handler(struct irq_desc *desc)
> +{
> + struct irq_domain *domain = irq_desc_get_handler_data(desc);
> + struct irq_chip_generic *gc = domain->gc->gc[0];
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + unsigned long pending;
> + int n;
> +
> + chained_irq_enter(chip, desc);
> +
> + pending = irq_reg_readl(gc, EXTI_PR);
> + for_each_set_bit(n, &pending, BITS_PER_LONG) {
> + generic_handle_irq(irq_find_mapping(domain, n));
> + }
> +
> + chained_irq_exit(chip, desc);
> +}
Is this one of those cases where you should re-read the status register
on every iteration, so as to avoid exiting and immediately re-entering
the irq handler?
C.g irq-vic.c:
static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs)
{
u32 stat, irq;
int handled = 0;
while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) {
irq = ffs(stat) - 1;
handle_domain_irq(vic->domain, irq, regs);
handled = 1;
}
return handled;
}
Yours,
Linus Walleij
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