2017-12-08 17:42:22

by Stefan Brüns

Subject: [PATCH v1 4/7] iio: adc: ina2xx: Do not udelay for several seconds

The conversion time can be up to 16 seconds (8 ms per channel, 2 channels,
1024 times averaging).

Signed-off-by: Stefan Brüns <[email protected]>
---

drivers/iio/adc/ina2xx-adc.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index b027d485398b..2621a34ee5c6 100644
--- a/drivers/iio/adc/ina2xx-adc.c
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -764,7 +764,7 @@ static int ina2xx_capture_thread(void *data)
struct iio_dev *indio_dev = data;
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
int sampling_us = SAMPLING_PERIOD(chip);
- int buffer_us;
+ int buffer_us, delay_us;

/*
* Poll a bit faster than the chip internal Fs, in case
@@ -778,8 +778,10 @@ static int ina2xx_capture_thread(void *data)
if (buffer_us < 0)
return buffer_us;

- if (sampling_us > buffer_us)
- udelay(sampling_us - buffer_us);
+ if (sampling_us > buffer_us) {
+ delay_us = sampling_us - buffer_us;
+ usleep_range(delay_us, (delay_us * 3) >> 1);
+ }

} while (!kthread_should_stop());

--
2.15.1

2017-12-17 11:54:05

by Jonathan Cameron

Subject: Re: [PATCH v1 4/7] iio: adc: ina2xx: Do not udelay for several seconds

On Fri, 8 Dec 2017 18:41:49 +0100
Stefan Brüns <[email protected]> wrote:

> The conversion time can be up to 16 seconds (8 ms per channel, 2 channels,
> 1024 times averaging).
>
> Signed-off-by: Stefan Brüns <[email protected]>
Applied
> ---
>
> drivers/iio/adc/ina2xx-adc.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
> index b027d485398b..2621a34ee5c6 100644
> --- a/drivers/iio/adc/ina2xx-adc.c
> +++ b/drivers/iio/adc/ina2xx-adc.c
> @@ -764,7 +764,7 @@ static int ina2xx_capture_thread(void *data)
> struct iio_dev *indio_dev = data;
> struct ina2xx_chip_info *chip = iio_priv(indio_dev);
> int sampling_us = SAMPLING_PERIOD(chip);
> - int buffer_us;
> + int buffer_us, delay_us;
>
> /*
> * Poll a bit faster than the chip internal Fs, in case
> @@ -778,8 +778,10 @@ static int ina2xx_capture_thread(void *data)
> if (buffer_us < 0)
> return buffer_us;
>
> - if (sampling_us > buffer_us)
> - udelay(sampling_us - buffer_us);
> + if (sampling_us > buffer_us) {
> + delay_us = sampling_us - buffer_us;
> + usleep_range(delay_us, (delay_us * 3) >> 1);
> + }
>
> } while (!kthread_should_stop());
>