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Wed, 11 Nov 2026 22:50:07 -0800 (PST) Received: from dtor-ws.sjc.corp.google.com ([2a00:79e0:2ebe:8:182d:659:ffce:39a4]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-37520cfdfadsm27190961eec.19.2026.11.11.22.50.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Nov 2026 22:50:06 -0800 (PST) From: Dmitry Torokhov To: Linus Walleij , Aaro Koskinen , Daniel Mack , Haojian Zhuang , Robert Jarzmik , Arnd Bergmann Cc: Mark Brown , "H . Nikolaus Schaller" , Kris Bahnsen , Mark Featherston , Bartosz Golaszewski , linux-input@vger.kernel.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/5] Input: ads7846 - remove unneeded memory barriers Date: Wed, 11 Nov 2026 22:49:55 -0800 Message-ID: <20261112064957.1796975-4-dmitry.torokhov@gmail.com> X-Mailer: git-send-email 2.56.0.567.gdb80ae8cd5-goog In-Reply-To: <20261112064957.1796975-1-dmitry.torokhov@gmail.com> References: <20261112064957.1796975-1-dmitry.torokhov@gmail.com> X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The driver invokes mb() after setting the stopped flag in ads7846_stop() and ads7846_restart(). These mandatory barriers lack pairing barriers on the reader side and are unnecessary. The wait queue operations wake_up() and wait_event_timeout(), along with disable_irq() and enable_irq(), already provide the required synchronization and memory ordering when stopping and restarting the device polling. Remove the redundant barriers. Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/ads7846.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index f1827684c902..6352117cd898 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -235,7 +235,6 @@ static void ads7846_stop(struct ads7846 *ts) if (!ts->disabled && !ts->suspended) { /* Signal IRQ thread to stop polling and disable the handler. */ ts->stopped = true; - mb(); wake_up(&ts->wait); disable_irq(ts->spi->irq); } @@ -251,7 +250,6 @@ static void ads7846_restart(struct ads7846 *ts) /* Tell IRQ thread that it may poll the device. */ ts->stopped = false; - mb(); enable_irq(ts->spi->irq); } } -- 2.56.0.567.gdb80ae8cd5-goog