diff options
| author | Fabrice Gasnier <fabrice.gasnier@st.com> | 2018-03-13 17:23:05 +0300 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2018-03-18 01:32:31 +0300 |
| commit | 7531cf59bfa082769887ec70c2029838ea139f11 (patch) | |
| tree | a2fca46b73389c59e35c90e582e2bdf9692c5062 /drivers/iio | |
| parent | 490fba90a90eb7b741f57fefd2bcf2c1e11eb471 (diff) | |
| download | linux-7531cf59bfa082769887ec70c2029838ea139f11.tar.xz | |
iio: adc: stm32-dfsdm: fix successive oversampling settings
When doing successive oversampling settings, it may fail to update filter
parameters silently:
- First time oversampling is being set, it will be successful, as fl->res
is 0 initially.
- Next attempts with various oversamp value may return 0 (success), but
keep previous filter parameters, due to 'res' never reaches above or
equal current 'fl->res'.
This is particularly true when setting sampling frequency (that relies on
oversamp). Typical failure without error:
- run 1st test @16kHz samp freq will succeed
- run new test @8kHz will succeed as well
- run new test @16kHz (again): sample rate will remain 8kHz without error
Fixes: e2e6771c6462 ("IIO: ADC: add STM32 DFSDM sigma delta ADC support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/adc/stm32-dfsdm-adc.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 01422d11753c..dc911b6fedd6 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -144,6 +144,7 @@ static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, * Leave as soon as if exact resolution if reached. * Otherwise the higher resolution below 32 bits is kept. */ + fl->res = 0; for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) { for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) { if (fast) @@ -193,7 +194,7 @@ static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl, } } - if (!fl->fosr) + if (!fl->res) return -EINVAL; return 0; |