linux-kernel - Re: [PATCH v3 3/5] gpiolib: cdev: reduce locking in gpio_desc_to

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Message-ID: <ZXyAh2hfhb3l5ogO@smile.fi.intel.com>
Date: Fri, 15 Dec 2023 18:36:23 +0200
From: Andy Shevchenko <andy@...nel.org>
To: Kent Gibson <warthog618@...il.com>
Cc: linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org, brgl@...ev.pl,
	linus.walleij@...aro.org
Subject: Re: [PATCH v3 3/5] gpiolib: cdev: reduce locking in
 gpio_desc_to_lineinfo()

On Fri, Dec 15, 2023 at 10:38:03AM +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 availability of the line from pinctrl if other checks
> pass, so avoiding the check for lines that are otherwise in use.

Just wondering if you are using --histogram (diff algo) when preparing
the patches...

-- 
With Best Regards,
Andy Shevchenko