Re: [RFC 4/4] gpio: sifive: Add GPIO driver for SiFive SoCs

From: Andreas Schwab
Date: Wed Oct 10 2018 - 09:28:55 EST


On Okt 10 2018, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:

> On Wed, Oct 10, 2018 at 03:01:29PM +0200, Andreas Schwab wrote:
>> On Okt 09 2018, Atish Patra <atish.patra@xxxxxxx> wrote:
>>
>> > +static void sifive_set_ie(struct sifive_gpio *chip, unsigned int offset)
>> > +{
>> > + unsigned long flags;
>> > + unsigned int trigger;
>> > +
>> > + raw_spin_lock_irqsave(&chip->lock, flags);
>> > + trigger = (chip->enabled & BIT(offset)) ? chip->trigger[offset] : 0;
>>
>> This should use test_bit instead.
>
> Given that this apparently needs the spinlock for atomciy with more than
> just the bitmap test_bit would be rather pointless.

BIT and test_bit/assign_bit are not compatible.

Andreas.

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Andreas Schwab, SUSE Labs, schwab@xxxxxxx
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