6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nuno Sa <nuno.sa@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Reviewed-by: David Lechner <dlechner@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231207-iio-backend-prep-v2-3-a4a33bc4d70e@xxxxxxxxxx
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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)
--
2.43.0
