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Groups > linux.kernel > #1457705 > unrolled thread
| Started by | Vignesh R <vigneshr@ti.com> |
|---|---|
| First post | 2016-08-08 13:10 +0200 |
| Last post | 2016-08-09 11:40 +0200 |
| Articles | 2 — 2 participants |
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[PATCH 2/2] iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample Vignesh R <vigneshr@ti.com> - 2016-08-08 13:10 +0200
Re: [PATCH 2/2] iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample Lee Jones <lee.jones@linaro.org> - 2016-08-09 11:40 +0200
| From | Vignesh R <vigneshr@ti.com> |
|---|---|
| Date | 2016-08-08 13:10 +0200 |
| Subject | [PATCH 2/2] iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample |
| Message-ID | <s3QBs-A4-7@gated-at.bofh.it> |
Now that open delay and sample delay for each channel is configurable
via DT, the default IDLE_TIMEOUT value is not enough as this is
calculated based on hardcoded macros. This results in driver returning
EBUSY sometimes. Fix this by increasing the timeout
value based on maximum value possible to open delay and sample delays
for each channel.
Signed-off-by: Vignesh R <vigneshr@ti.com>
---
drivers/iio/adc/ti_am335x_adc.c | 2 +-
include/linux/mfd/ti_am335x_tscadc.h | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index bed9977a1863..c3cfacca2541 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -381,7 +381,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
- timeout = jiffies + usecs_to_jiffies
+ timeout = jiffies + msecs_to_jiffies
(IDLE_TIMEOUT * adc_dev->channels);
/* Wait for Fifo threshold interrupt */
while (1) {
diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
index 2567a87872b0..7f55b8b41032 100644
--- a/include/linux/mfd/ti_am335x_tscadc.h
+++ b/include/linux/mfd/ti_am335x_tscadc.h
@@ -138,16 +138,16 @@
/*
* time in us for processing a single channel, calculated as follows:
*
- * num cycles = open delay + (sample delay + conv time) * averaging
+ * max num cycles = open delay + (sample delay + conv time) * averaging
*
- * num cycles: 152 + (1 + 13) * 16 = 376
+ * max num cycles: 262143 + (255 + 13) * 16 = 266431
*
* clock frequency: 26MHz / 8 = 3.25MHz
* clock period: 1 / 3.25MHz = 308ns
*
- * processing time: 376 * 308ns = 116us
+ * max processing time: 266431 * 308ns = 83ms(approx)
*/
-#define IDLE_TIMEOUT 116 /* microsec */
+#define IDLE_TIMEOUT 83 /* milliseconds */
#define TSCADC_CELLS 2
--
2.9.2
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| From | Lee Jones <lee.jones@linaro.org> |
|---|---|
| Date | 2016-08-09 11:40 +0200 |
| Subject | Re: [PATCH 2/2] iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample |
| Message-ID | <s4bFT-5HW-1@gated-at.bofh.it> |
| In reply to | #1457705 |
On Mon, 08 Aug 2016, Vignesh R wrote:
> Now that open delay and sample delay for each channel is configurable
> via DT, the default IDLE_TIMEOUT value is not enough as this is
> calculated based on hardcoded macros. This results in driver returning
> EBUSY sometimes. Fix this by increasing the timeout
> value based on maximum value possible to open delay and sample delays
> for each channel.
>
> Signed-off-by: Vignesh R <vigneshr@ti.com>
> ---
> drivers/iio/adc/ti_am335x_adc.c | 2 +-
> include/linux/mfd/ti_am335x_tscadc.h | 8 ++++----
Acked-by: Lee Jones <lee.jones@linaro.org>
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> index bed9977a1863..c3cfacca2541 100644
> --- a/drivers/iio/adc/ti_am335x_adc.c
> +++ b/drivers/iio/adc/ti_am335x_adc.c
> @@ -381,7 +381,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
>
> am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
>
> - timeout = jiffies + usecs_to_jiffies
> + timeout = jiffies + msecs_to_jiffies
> (IDLE_TIMEOUT * adc_dev->channels);
> /* Wait for Fifo threshold interrupt */
> while (1) {
> diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h
> index 2567a87872b0..7f55b8b41032 100644
> --- a/include/linux/mfd/ti_am335x_tscadc.h
> +++ b/include/linux/mfd/ti_am335x_tscadc.h
> @@ -138,16 +138,16 @@
> /*
> * time in us for processing a single channel, calculated as follows:
> *
> - * num cycles = open delay + (sample delay + conv time) * averaging
> + * max num cycles = open delay + (sample delay + conv time) * averaging
> *
> - * num cycles: 152 + (1 + 13) * 16 = 376
> + * max num cycles: 262143 + (255 + 13) * 16 = 266431
> *
> * clock frequency: 26MHz / 8 = 3.25MHz
> * clock period: 1 / 3.25MHz = 308ns
> *
> - * processing time: 376 * 308ns = 116us
> + * max processing time: 266431 * 308ns = 83ms(approx)
> */
> -#define IDLE_TIMEOUT 116 /* microsec */
> +#define IDLE_TIMEOUT 83 /* milliseconds */
>
> #define TSCADC_CELLS 2
>
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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