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Sun, 06 Sep 2026 04:42:46 -0700 (PDT) From: Abdelnasser Hussein To: gregkh@linuxfoundation.org, jic23@kernel.org, nuno.sa@analog.com, Michael.Hennerich@analog.com Cc: dlechner@baylibre.com, andy@kernel.org, linux@analog.com, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Abdelnasser Hussein Subject: [PATCH v4 1/2] staging: iio: adc: ad7816: Serialize SPI read operations Date: Sun, 6 Sep 2026 14:40:48 +0300 Message-ID: <20260906114049.32912-2-abdelnasserhussein11@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260906114049.32912-1-abdelnasserhussein11@gmail.com> References: <20260906114049.32912-1-abdelnasserhussein11@gmail.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a mutex to serialize SPI read operations and prevent data corruption. Used guard(mutex) and devm_mutex_init() for safer and automatic cleanup. Signed-off-by: Abdelnasser Hussein --- drivers/staging/iio/adc/ad7816.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c index 0e32a2295990..ab80b3a889bb 100644 --- a/drivers/staging/iio/adc/ad7816.c +++ b/drivers/staging/iio/adc/ad7816.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include #include @@ -65,7 +67,8 @@ static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data) { struct spi_device *spi_dev = chip->spi_dev; int ret; - __be16 buf; + + guard(mutex)(&chip->lock); gpiod_set_value(chip->rdwr_pin, 1); gpiod_set_value(chip->rdwr_pin, 0); @@ -360,6 +363,10 @@ static int ad7816_probe(struct spi_device *spi_dev) return -ENOMEM; chip = iio_priv(indio_dev); + ret = devm_mutex_init(&spi_dev->dev, &chip->lock); + if (ret) + return ret; + chip->spi_dev = spi_dev; for (i = 0; i <= AD7816_CS_MAX; i++) chip->oti_data[i] = 203; -- 2.54.0