linux-kernel - Re: [PATCH v3] gpiolib: sysfs: Fix error handling on failed export

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Message-ID: <ZWdia1rDg9pH2Fhu@smile.fi.intel.com>
Date:   Wed, 29 Nov 2023 18:10:19 +0200
From:   Andy Shevchenko <andy@...nel.org>
To:     Boerge Struempfel <boerge.struempfel@...il.com>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Andrew Jeffery <andrew@...id.au>,
        Charles Keepax <ckeepax@...nsource.cirrus.com>,
        Rob Herring <robh@...nel.org>, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org, bstruempfel@...ratronik.de
Subject: Re: [PATCH v3] gpiolib: sysfs: Fix error handling on failed export

On Wed, Nov 29, 2023 at 04:23:07PM +0100, Boerge Struempfel wrote:
> If gpio_set_transitory() fails, we should free the GPIO again. Most
> notably, the flag FLAG_REQUESTED has previously been set in
> gpiod_request_commit(), and should be reset on failure.
> 
> To my knowledge, this does not affect any current users, since the
> gpio_set_transitory() mainly returns 0 and -ENOTSUPP, which is converted
> to 0. However the gpio_set_transitory() function calles the .set_config()
> function of the corresponding GPIO chip and there are some GPIO drivers in
> which some (unlikely) branches return other values like -EPROBE_DEFER,
> and -EINVAL. In these cases, the above mentioned FLAG_REQUESTED would not
> be reset, which results in the pin being blocked until the next reboot.

Thank you!
Reviewed-by: Andy Shevchenko <andy@...nel.org>

-- 
With Best Regards,
Andy Shevchenko