diff options
| author | Vignesh R <vigneshr@ti.com> | 2016-08-17 17:43:01 +0530 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-08-21 19:48:31 +0100 |
| commit | 7175cce1c3f1d8c8840d2004f78f96a3904249b5 (patch) | |
| tree | 1943c8cf16ab4075753629fe273aba2ee51bba96 | |
| parent | 90c43ec6997a892448f1f86180a515f59cafd8a3 (diff) | |
| download | op-kernel-dev-7175cce1c3f1d8c8840d2004f78f96a3904249b5.zip op-kernel-dev-7175cce1c3f1d8c8840d2004f78f96a3904249b5.tar.gz | |
iio: adc: ti_am335x_adc: Increase timeout value waiting for ADC sample
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.
Fixes: 5dc11e810676e ("iio: adc: ti_am335x_adc: make sample delay, open delay, averaging DT parameters")
Signed-off-by: Vignesh R <vigneshr@ti.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
| -rw-r--r-- | drivers/iio/adc/ti_am335x_adc.c | 2 | ||||
| -rw-r--r-- | 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 bed9977..c3cfacc 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 2567a87..7f55b8b 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 |
