Re: [PATCH 7/7 v2] gpio: dwapb: use d->mask instead od BIT(bit)

From: Joe Perches
Date: Tue Mar 25 2014 - 17:25:31 EST


On Tue, 2014-03-25 at 22:18 +0100, Sebastian Andrzej Siewior wrote:
> d->mask contains exact the same information as BIT(bit) so we could save
> a few cycles here.

I think you actually lose a few cycles here as
the pointer has to be dereferenced for each use.

> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
[]
> @@ -171,24 +170,24 @@ static int dwapb_irq_set_type(struct irq_data *d, u32 type)
>
> switch (type) {
> case IRQ_TYPE_EDGE_BOTH:
> - level |= BIT(bit);
> - dwapb_toggle_trigger(gpio, bit);
> + level |= d->mask;
> + dwapb_toggle_trigger(gpio, d->hwirq);
> break;
> case IRQ_TYPE_EDGE_RISING:
> - level |= BIT(bit);
> - polarity |= BIT(bit);
> + level |= d->mask;
> + polarity |= d->mask;
> break;
> case IRQ_TYPE_EDGE_FALLING:
> - level |= BIT(bit);
> - polarity &= ~BIT(bit);
> + level |= d->mask;
> + polarity &= ~d->mask;
> break;
> case IRQ_TYPE_LEVEL_HIGH:
> - level &= ~BIT(bit);
> - polarity |= BIT(bit);
> + level &= ~d->mask;
> + polarity |= d->mask;
> break;
> case IRQ_TYPE_LEVEL_LOW:
> - level &= ~BIT(bit);
> - polarity &= ~BIT(bit);
> + level &= ~d->mask;
> + polarity &= ~d->mask;
> break;
> }
>



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