Re: [PATCH 05/10] mfd: menelaus: Use for_each_set_bit()

From: Joe Perches
Date: Mon Dec 16 2013 - 19:17:45 EST


On Mon, 2013-12-16 at 18:08 -0600, Felipe Balbi wrote:
> That macro just helps removing some extra line of code and hides ffs()
> calls.
>
> While at that, also fix a variable shadowing bug where 'int irq' was
> being redeclared inside inner loop while it was also argument to
> interrupt handler.
>
> Tested-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> ---
> drivers/mfd/menelaus.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mfd/menelaus.c b/drivers/mfd/menelaus.c
> index 87d80a8..d3e3022 100644
> --- a/drivers/mfd/menelaus.c
> +++ b/drivers/mfd/menelaus.c
> @@ -795,24 +795,22 @@ static irqreturn_t menelaus_irq(int irq, void *_menelaus)
> {
> struct menelaus_chip *menelaus = _menelaus;
> void (*handler)(struct menelaus_chip *menelaus);
> - unsigned isr;
> + unsigned long isr;
> + unsigned long i;
>
> isr = (menelaus_read_reg(MENELAUS_INT_STATUS2)
> & ~menelaus->mask2) << 8;
> isr |= menelaus_read_reg(MENELAUS_INT_STATUS1)
> & ~menelaus->mask1;
>
> - while (isr) {
> - int irq = fls(isr) - 1;
> - isr &= ~(1 << irq);
> -
> + for_each_set_bit(i, &isr, 16) {
> mutex_lock(&menelaus->lock);
> - menelaus_disable_irq(irq);
> - menelaus_ack_irq(irq);
> - handler = menelaus->handlers[irq];
> + menelaus_disable_irq(i);
> + menelaus_ack_irq(i);
> + handler = menelaus->handlers[i];
> if (handler)
> handler(menelaus);
> - menelaus_enable_irq(irq);
> + menelaus_enable_irq(i);
> mutex_unlock(&menelaus->lock);
> }
>

This could handle the irqs in reverse order.
Does that matter?

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