Messages in this thread | | | Date | Sat, 18 Jul 2015 10:20:53 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 3/3] clocksource: atmel-pit: Remove irq handler when clock event is unused |
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On Fri, 17 Jul 2015, Alexandre Belloni wrote: > /* > + * IRQ handler for the timer. > + */ > +static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id) > +{ > + struct pit_data *data = dev_id; > + > + /* > + * irqs should be disabled here, but as the irq is shared they are only > + * guaranteed to be off if the timer irq is registered first.
That's wrong. We run all handlers with interrupts disabled for about 5 years now.
> + */ > + WARN_ON_ONCE(!irqs_disabled());
> + /* The PIT interrupt may be disabled, and is shared */ > + if (clockevent_state_periodic(&data->clkevt) && > + (pit_read(data->base, AT91_PIT_SR) & AT91_PIT_PITS)) { > + unsigned nr_ticks; > + > + /* Get number of ticks performed before irq, and ack it */ > + nr_ticks = PIT_PICNT(pit_read(data->base, AT91_PIT_PIVR)); > + do { > + data->cnt += data->cycle; > + data->clkevt.event_handler(&data->clkevt); > + nr_ticks--; > + } while (nr_ticks);
I don't think you need this loop. You have a proper clocksource registered so the timekeeping code will handle the lost ticks nicely.
Thanks,
tglx
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