RE: [PATCH v2 03/16] iio: adc: imx7d_adc: do not use internal iio_dev lock

Bough Chen
2022-10-09T02:00:30Z

> -----Original Message-----
> From: Nuno Sá <nuno.sa@analog.com>
> Sent: 2022年10月4日 21:49
> To: linux-amlogic@lists.infradead.org; dl-linux-imx <linux-imx@nxp.com>;
> linux-iio@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> linux-rockchip@lists.infradead.org
> Cc: Heiko Stuebner <heiko@sntech.de>; Martin Blumenstingl
> <martin.blumenstingl@googlemail.com>; Neil Armstrong
> <narmstrong@baylibre.com>; Shawn Guo <shawnguo@kernel.org>; Lars-Peter
> Clausen <lars@metafoo.de>; Jyoti Bhayana <jbhayana@google.com>; Hans de
> Goede <hdegoede@redhat.com>; Andriy Tryshnivskyy
> <andriy.tryshnivskyy@opensynergy.com>; Pengutronix Kernel Team
> <kernel@pengutronix.de>; Miquel Raynal <miquel.raynal@bootlin.com>; Cixi
> Geng <cixi.geng1@unisoc.com>; Baolin Wang
> <baolin.wang@linux.alibaba.com>; Ciprian Regus <ciprian.regus@analog.com>;
> Fabio Estevam <festevam@gmail.com>; Nuno Sá <nuno.sa@analog.com>;
> Sascha Hauer <s.hauer@pengutronix.de>; Alexandru Ardelean
> <aardelean@deviqon.com>; Florian Boor <florian.boor@kernelconcepts.de>;
> Michael Hennerich <Michael.Hennerich@analog.com>; Orson Zhai
> <orsonzhai@gmail.com>; Chen-Yu Tsai <wens@csie.org>; Chunyan Zhang
> <zhang.lyra@gmail.com>; Vladimir Zapolskiy <vz@mleia.com>; Andy
> Shevchenko <andy.shevchenko@gmail.com>; Jerome Brunet
> <jbrunet@baylibre.com>; Bough Chen <haibo.chen@nxp.com>; Kevin Hilman
> <khilman@baylibre.com>; Jonathan Cameron <jic23@kernel.org>
> Subject: [PATCH v2 03/16] iio: adc: imx7d_adc: do not use internal iio_dev lock
>
> The iio_device lock is only meant for internal use. Hence define a device local
> lock to protect against concurrent accesses.
>
> While at it, properly include "mutex.h" for mutex related APIs.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>

Reviewed-by: Haibo Chen <haibo.chen@nxp.com>

Thanks!
Best Regards
Haibo Chen
> ---
> drivers/iio/adc/imx7d_adc.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c index
> 86caff1d006b..22da81bac97f 100644
> --- a/drivers/iio/adc/imx7d_adc.c
> +++ b/drivers/iio/adc/imx7d_adc.c
> @@ -13,6 +13,7 @@
> #include <linux/kernel.h>
> #include <linux/mod_devicetable.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> #include <linux/platform_device.h>
> #include <linux/regulator/consumer.h>
>
> @@ -108,7 +109,8 @@ struct imx7d_adc {
> struct device *dev;
> void __iomem *regs;
> struct clk *clk;
> -
> + /* lock to protect against multiple access to the device */
> + struct mutex lock;
> u32 vref_uv;
> u32 value;
> u32 channel;
> @@ -293,7 +295,7 @@ static int imx7d_adc_read_raw(struct iio_dev
> *indio_dev,
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&info->lock);
> reinit_completion(&info->completion);
>
> channel = chan->channel & 0x03;
> @@ -303,16 +305,16 @@ static int imx7d_adc_read_raw(struct iio_dev
> *indio_dev,
> ret = wait_for_completion_interruptible_timeout
> (&info->completion, IMX7D_ADC_TIMEOUT);
> if (ret == 0) {
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&info->lock);
> return -ETIMEDOUT;
> }
> if (ret < 0) {
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&info->lock);
> return ret;
> }
>
> *val = info->value;
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&info->lock);
> return IIO_VAL_INT;
>
> case IIO_CHAN_INFO_SCALE:
> @@ -531,6 +533,8 @@ static int imx7d_adc_probe(struct platform_device
> *pdev)
> if (ret)
> return ret;
>
> + mutex_init(&info->lock);
> +
> ret = devm_iio_device_register(dev, indio_dev);
> if (ret) {
> dev_err(&pdev->dev, "Couldn't register the device.\n");
> --
> 2.37.3