[v1] iio: adc: ad7192: replace usleep_range() with fsleep()

[PATCH] iio: adc: ad7192: replace usleep_range() with fsleep()

Posted by Stepan Ionichev 2 weeks, 6 days ago

The "at least 500us" wait after serial interface reset has no specific
upper bound. fsleep(500) expands to the same usleep_range(500, 1000)
internally and is the kernel helper for plain "about N microseconds"
delays.

No functional change.

Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
---
 drivers/iio/adc/ad7192.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 8b1664f6b..712004ab5 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -576,7 +576,7 @@ static int ad7192_setup(struct iio_dev *indio_dev, struct device *dev)
 	ret = ad_sd_reset(&st->sd);
 	if (ret < 0)
 		return ret;
-	usleep_range(500, 1000); /* Wait for at least 500us */
+	fsleep(500); /* Wait for at least 500us */
 
 	/* write/read test for device presence */
 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
-- 
2.43.0

Re: [PATCH] iio: adc: ad7192: replace usleep_range() with fsleep()

Posted by Andy Shevchenko 2 weeks, 5 days ago

On Sun, May 10, 2026 at 10:24:01AM +0500, Stepan Ionichev wrote:
> The "at least 500us" wait after serial interface reset has no specific
> upper bound. fsleep(500) expands to the same usleep_range(500, 1000)
> internally and is the kernel helper for plain "about N microseconds"
> delays.
> 
> No functional change.

...

> -	usleep_range(500, 1000); /* Wait for at least 500us */
> +	fsleep(500); /* Wait for at least 500us */

This is useless comment, I can see it from the code. Better comment to explain
"why?" and ideally with a reference to a datasheet.

-- 
With Best Regards,
Andy Shevchenko

[PATCH v2] iio: adc: ad7192: replace usleep_range() with fsleep()

Posted by Stepan Ionichev 2 weeks, 6 days ago

The "at least 500us" wait after serial interface reset has no
specific upper bound. fsleep(500) expands to the same
usleep_range(500, 1000) internally.

Drop the trailing "/* Wait for at least 500us */" comment which
just restated the previous arguments.

No functional change.

Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
---
 drivers/iio/adc/ad7192.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index 8b1664f6b..6bd9cdaa6 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -576,7 +576,7 @@ static int ad7192_setup(struct iio_dev *indio_dev, struct device *dev)
 	ret = ad_sd_reset(&st->sd);
 	if (ret < 0)
 		return ret;
-	usleep_range(500, 1000); /* Wait for at least 500us */
+	fsleep(500);
 
 	/* write/read test for device presence */
 	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
-- 
2.43.0

Re: [PATCH v2] iio: adc: ad7192: replace usleep_range() with fsleep()

Posted by Andy Shevchenko 2 weeks, 5 days ago

On Sun, May 10, 2026 at 10:54:17AM +0500, Stepan Ionichev wrote:
> The "at least 500us" wait after serial interface reset has no
> specific upper bound. fsleep(500) expands to the same
> usleep_range(500, 1000) internally.
> 
> Drop the trailing "/* Wait for at least 500us */" comment which
> just restated the previous arguments.
> 
> No functional change.

> Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
> ---

You missed a changelog here.

>  1 file changed, 1 insertion(+), 1 deletion(-)

...

> -	usleep_range(500, 1000); /* Wait for at least 500us */
> +	fsleep(500);

Have you checked the datasheet? What does it say about this sleep?

-- 
With Best Regards,
Andy Shevchenko