[v2,2/2] staging: iio: adc: ad7192: add lock to protect hardware state changes
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Message ID 1506440468-5081-3-git-send-email-aastha.gupta4104@gmail.com
State New
Headers show

Commit Message

Aastha Gupta Sept. 26, 2017, 3:41 p.m. UTC
The IIO subsystem is redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.

In this driver, private driver lock is being used to protect hardware
state changes as here state variables are being changed.

Signed-off-by: Aastha Gupta <aastha.gupta4104@gmail.com>
---
 drivers/staging/iio/adc/ad7192.c | 2 ++
 1 file changed, 2 insertions(+)

Patch
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diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index 096d29d..609a649 100644
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -511,6 +511,7 @@  static int ad7192_write_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		ret = -EINVAL;
+		mutex_lock(&st->lock);
 		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
 			if (val2 == st->scale_avail[i][1]) {
 				ret = 0;
@@ -524,6 +525,7 @@  static int ad7192_write_raw(struct iio_dev *indio_dev,
 				ad7192_calibrate_all(st);
 				break;
 			}
+		mutex_unlock(&st->lock);
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (!val) {