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Date:   Thu, 20 Jan 2022 09:44:52 +0200
From:   Mika Westerberg <mika.westerberg@linux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andy Shevchenko <andy@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Kane Chen <kane.chen@intel.com>
Subject: Re: [PATCH v1 1/1] pinctrl: intel: Fix a glitch when updating IRQ
 flags on a preconfigured line
Message-ID: <YekS9O5Xhl6VL9GM@lahna>
References: <20220119181915.27519-1-andriy.shevchenko@linux.intel.com>
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In-Reply-To: <20220119181915.27519-1-andriy.shevchenko@linux.intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
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On Wed, Jan 19, 2022 at 08:19:15PM +0200, Andy Shevchenko wrote:
> The commit af7e3eeb84e2 ("pinctrl: intel: Disable input and output buffer
> when switching to GPIO") hadn't taken into account an update of the IRQ
> flags scenario.
> 
> When updating the IRQ flags on the preconfigured line the ->irq_set_type()
> is called again. In such case the sequential Rx buffer configuration
> changes may trigger a falling or rising edge interrupt that may lead,
> on some platforms, to an undesired event.
> 
> This may happen because each of intel_gpio_set_gpio_mode() and
> __intel_gpio_set_direction() updates the pad configuration with a different
> value of the GPIORXDIS bit. Notable, that the intel_gpio_set_gpio_mode() is
> called only for the pads that are configured as an input. Due to this fact,
> integrate the logic of __intel_gpio_set_direction() call into the
> intel_gpio_set_gpio_mode() so that the Rx buffer won't be disabled and
> immediately re-enabled.
> 
> Fixes: af7e3eeb84e2 ("pinctrl: intel: Disable input and output buffer when switching to GPIO")
> Reported-by: Kane Chen <kane.chen@intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Please mark this for stable too.