Re: [PATCH 3/4] gpiolib: cdev: reduce locking in gpio_desc_to_lineinfo()

From: Andy Shevchenko
Date: Wed Dec 13 2023 - 08:59:04 EST


On Tue, Dec 12, 2023 at 01:42:52PM +0800, Kent Gibson wrote:
> Reduce the time holding the gpio_lock by snapshotting the desc flags,
> rather than testing them individually while holding the lock.
>
> Accept that the calculation of the used field is inherently racy, and
> only check the availabilty of the line from pinctrl if other checks
> pass, so avoiding the check for lines that are otherwise in use.

...

> - bool ok_for_pinctrl;
> - unsigned long flags;
> + unsigned long iflags, dflags;

With a preliminary conversion to cleanup.h this whole change becomes cleaner,
no?

--
With Best Regards,
Andy Shevchenko