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Message-ID: <20230814093934.1793961e@dellmb>
Date: Mon, 14 Aug 2023 09:39:34 +0200
From: Marek BehĂșn <kabel@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
linux-gpio@...r.kernel.org,
Linus Walleij <linus.walleij@...aro.org>,
linux-kernel@...r.kernel.org
Subject: Re: regression from commit b0ce9ce408b6 ("gpiolib: Do not unexport
GPIO on freeing")
On Fri, 11 Aug 2023 13:16:46 +0300
Andy Shevchenko <andriy.shevchenko@...ux.intel.com> wrote:
> On Tue, Aug 08, 2023 at 10:28:28AM +0200, Marek BehĂșn wrote:
> > Hi,
> >
> > the commit b0ce9ce408b6 ("gpiolib: Do not unexport GPIO on freeing")
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b0ce9ce408b6
> >
> > causes a regression on my mvebu arm board (haven't tested on other
> > systems), wherein if I export a GPIO to sysfs and then unexport it, it
> > does not disasppear from the /sys/class/gpio directory, and subsequent
> > writes to the export and unexport files for the gpio fail.
> >
> > $ cd /sys/class/gpio
> > $ ls
> > export gpiochip0 gpiochip32 gpiochip512 unexport
> > $ echo 43 >export
> > $ ls
> > export gpio43 gpiochip0 gpiochip32 gpiochip512
> > unexport
> > $ cat gpio43/value
> > 1
> > $ echo 43 >unexport
> > $ ls
> > export gpio43 gpiochip0 gpiochip32 gpiochip512
> > unexport
> > $ echo 43 >unexport
> > ash: write error: Invalid argument
> > $ echo 43 >export
> > ash: write error: Operation not permitted
>
> Can you test the following change (I'll submit a formal patch if it works)?
>
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> index 530dfd19d7b5..b10a9b5598b2 100644
> --- a/drivers/gpio/gpiolib-sysfs.c
> +++ b/drivers/gpio/gpiolib-sysfs.c
> @@ -515,8 +515,9 @@ static ssize_t unexport_store(const struct class *class,
> * they may be undone on its behalf too.
> */
> if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
> + gpiod_unexport(desc);
> + gpiod_free(desc);
> status = 0;
> - gpiod_free(desc);
> }
> done:
> if (status)
>
tested, works.
Please add Fixes tag when sending the patch
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