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Tue, 01 Sep 2026 11:26:09 -0700 (PDT) Sender: Guenter Roeck Date: Tue, 1 Sep 2026 11:26:09 -0700 From: Guenter Roeck To: Cong Nguyen Cc: Nishanth Menon , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, Sashiko AI review Subject: Re: [PATCH] hwmon: (gpio-fan) take fan_data->lock in gpio_fan_shutdown() Message-ID: <69118d15-39a2-4506-a5cf-e610957a0b4c@roeck-us.net> References: <20260901155404.1532092-1-congnt264@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260901155404.1532092-1-congnt264@gmail.com> On Tue, Sep 01, 2026 at 10:54:04PM +0700, Cong Nguyen wrote: > set_fan_speed() writes the control GPIOs one bit at a time. Every > other caller locks around it; gpio_fan_shutdown() doesn't. If it races > a locked caller, the GPIO writes can interleave and leave the fan at a > speed neither caller asked for. > > Fixes: b95579cd8795 ("hwmon: (gpio-fan) Add a shutdown handler to poweroff the fans") > Reported-by: Sashiko AI review > Link: https://lore.kernel.org/r/20260830152150.27F5F1F000E9@smtp.kernel.org > Assisted-by: Claude:claude-opus-4 > Signed-off-by: Cong Nguyen Applied. Thanks, Guenter