6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nuno Sa nuno.sa@analog.com
[ Upstream commit 737720197be445bb9eec2986101e4a386e019337 ]
When calling ad9467_set_scale(), multiple calls to ad9467_spi_write() are done which means we need to properly protect the whole operation so we are sure we will be in a sane state if two concurrent calls occur.
Fixes: ad6797120238 ("iio: adc: ad9467: add support AD9467 ADC") Signed-off-by: Nuno Sa nuno.sa@analog.com Reviewed-by: David Lechner dlechner@baylibre.com Link: https://lore.kernel.org/r/20231207-iio-backend-prep-v2-3-a4a33bc4d70e@analog... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/adc/ad9467.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/adc/ad9467.c b/drivers/iio/adc/ad9467.c index d3c98c4eccd3..104c6d394a3e 100644 --- a/drivers/iio/adc/ad9467.c +++ b/drivers/iio/adc/ad9467.c @@ -4,8 +4,9 @@ * * Copyright 2012-2020 Analog Devices Inc. */ - +#include <linux/cleanup.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/device.h> #include <linux/kernel.h> #include <linux/slab.h> @@ -121,6 +122,8 @@ struct ad9467_state { unsigned int output_mode;
struct gpio_desc *pwrdown_gpio; + /* ensure consistent state obtained on multiple related accesses */ + struct mutex lock; };
static int ad9467_spi_read(struct spi_device *spi, unsigned int reg) @@ -161,6 +164,7 @@ static int ad9467_reg_access(struct adi_axi_adc_conv *conv, unsigned int reg, int ret;
if (readval == NULL) { + guard(mutex)(&st->lock); ret = ad9467_spi_write(spi, reg, writeval); if (ret) return ret; @@ -310,6 +314,7 @@ static int ad9467_set_scale(struct adi_axi_adc_conv *conv, int val, int val2) if (scale_val[0] != val || scale_val[1] != val2) continue;
+ guard(mutex)(&st->lock); ret = ad9467_spi_write(st->spi, AN877_ADC_REG_VREF, info->scale_table[i][1]); if (ret < 0)