From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [80.237.130.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 49723173 for ; Sat, 18 Dec 2021 06:28:45 +0000 (UTC) Received: from ip4d173d4a.dynamic.kabel-deutschland.de ([77.23.61.74] helo=[192.168.66.200]); authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1myTD0-0007w5-0u; Sat, 18 Dec 2021 07:28:42 +0100 Message-ID: Date: Sat, 18 Dec 2021 07:28:41 +0100 Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.0 Subject: Re: [PATCH] gpio: Revert regression in sysfs-gpio (gpiolib.c) Content-Language: en-BS To: Marcelo Roberto Jimenez , stable@vger.kernel.org, regressions@lists.linux.dev, Linus Walleij , Bartosz Golaszewski , linux-gpio@vger.kernel.org, Thierry Reding , Vidya Sagar , Geert Uytterhoeven , Stephen Rothwell , Edmond Chung , Andrew Chant , Will McVicker , Sergio Tanzilli References: <20211217153555.9413-1-marcelo.jimenez@gmail.com> From: Thorsten Leemhuis In-Reply-To: <20211217153555.9413-1-marcelo.jimenez@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1639808925;596d9f34; X-HE-SMSGID: 1myTD0-0007w5-0u [TLDR: I'm adding this regression to regzbot, the Linux kernel regression tracking bot; most text you find below is compiled from a few templates paragraphs some of you might have seen already.] On 17.12.21 16:35, Marcelo Roberto Jimenez wrote: > Some GPIO lines have stopped working after the patch > commit 2ab73c6d8323f ("gpio: Support GPIO controllers without pin-ranges") > > And this has supposedly been fixed in the following patches > commit 89ad556b7f96a ("gpio: Avoid using pin ranges with !PINCTRL") > commit 6dbbf84603961 ("gpiolib: Don't free if pin ranges are not defined") There seems to be a backstory here. Are there any entries and bug trackers or earlier discussions everyone that looks into this should be aware of? > But an erratic behavior where some GPIO lines work while others do not work > has been introduced. > > This patch reverts those changes so that the sysfs-gpio interface works > properly again. > > Signed-off-by: Marcelo Roberto Jimenez > --- > > Hi, > > My system is ARM926EJ-S rev 5 (v5l) (AT91SAM9G25), the board is an ACME Systems Arietta. > > The system used sysfs-gpio to manage a few gpio lines, and I have noticed that some have stopped working. > > The test script is very simple: > > #! /bin/bash > > cd /sys/class/gpio/ > echo 24 > export > > cd pioA24 > echo out > direction > > echo 0 > value > cat value > echo 1 > value > cat value > echo 0 > value > cat value > echo 1 > value > cat value > > cd .. > echo 24 > unexport > > In a "good" kernel, this script outputs 0, 1, 0, 1. In a bad kernel, the output result is 1, 1, 1, 1. Also it must be possible to run this script twice without errors, that was the issue with the gpiochip_generic_free() call that had been addressed in another patch. > > In my system PINCTRL is automatically selected by > SOC_AT91SAM9 [=y] && ARCH_AT91 [=y] && ARCH_MULTI_V5 [=y] > > So it is not an option to disable it to make it work. > > Best regards, > Marcelo. > > > drivers/gpio/gpiolib.c | 10 ---------- > 1 file changed, 10 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index af5bb8fedfea..ac69ec8fb37a 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -1804,11 +1804,6 @@ static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) > */ > int gpiochip_generic_request(struct gpio_chip *gc, unsigned offset) > { > -#ifdef CONFIG_PINCTRL > - if (list_empty(&gc->gpiodev->pin_ranges)) > - return 0; > -#endif > - > return pinctrl_gpio_request(gc->gpiodev->base + offset); > } > EXPORT_SYMBOL_GPL(gpiochip_generic_request); > @@ -1820,11 +1815,6 @@ EXPORT_SYMBOL_GPL(gpiochip_generic_request); > */ > void gpiochip_generic_free(struct gpio_chip *gc, unsigned offset) > { > -#ifdef CONFIG_PINCTRL > - if (list_empty(&gc->gpiodev->pin_ranges)) > - return; > -#endif > - > pinctrl_gpio_free(gc->gpiodev->base + offset); > } > EXPORT_SYMBOL_GPL(gpiochip_generic_free); > Hi, this is your Linux kernel regression tracker speaking. Thanks for the report. To be sure this issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression tracking bot: #regzbot ^introduced 2ab73c6d8323f #regzbot title gpio: some GPIO lines have stopped working #regzbot ignore-activity Reminder: when fixing the issue, please add a 'Link:' tag with the URL to the report (the parent of this mail), as explained in 'Documentation/process/submitting-patches.rst' (reminder: you should use the kernel.org redirector). Regzbot then will automatically mark the regression as resolved once the fix lands in the appropriate tree. For more details about regzbot see footer. Sending this to everyone that got the initial report, to make all aware of the tracking. I also hope that messages like this motivate people to directly get at least the regression mailing list and ideally even regzbot involved when dealing with regressions, as messages like this wouldn't be needed then. Don't worry, I'll send further messages wrt to this regression just to the lists (with a tag in the subject so people can filter them away), as long as they are intended just for regzbot. With a bit of luck no such messages will be needed anyway. Ciao, Thorsten (wearing his 'Linux kernel regression tracker' hat). P.S.: As a Linux kernel regression tracker I'm getting a lot of reports on my table. I can only look briefly into most of them. Unfortunately therefore I sometimes will get things wrong or miss something important. I hope that's not the case here; if you think it is, don't hesitate to tell me about it in a public reply. That's in everyone's interest, as what I wrote above might be misleading to everyone reading this; any suggestion I gave thus might sent someone reading this down the wrong rabbit hole, which none of us wants. BTW, I have no personal interest in this issue, which is tracked using regzbot, my Linux kernel regression tracking bot (https://linux-regtracking.leemhuis.info/regzbot/). I'm only posting this mail to get things rolling again and hence don't need to be CC on all further activities wrt to this regression. --- Additional information about regzbot: If you want to know more about regzbot, check out its web-interface, the getting start guide, and/or the references documentation: https://linux-regtracking.leemhuis.info/regzbot/ https://gitlab.com/knurd42/regzbot/-/blob/main/docs/getting_started.md https://gitlab.com/knurd42/regzbot/-/blob/main/docs/reference.md The last two documents will explain how you can interact with regzbot yourself if your want to. Hint for reporters: when reporting a regression it's in your interest to tell #regzbot about it in the report, as that will ensure the regression gets on the radar of regzbot and the regression tracker. That's in your interest, as they will make sure the report won't fall through the cracks unnoticed. Hint for developers: you normally don't need to care about regzbot once it's involved. Fix the issue as you normally would, just remember to include a 'Link:' tag to the report in the commit message, as explained in Documentation/process/submitting-patches.rst That aspect was recently was made more explicit in commit 1f57bd42b77c: https://git.kernel.org/linus/1f57bd42b77c