| Message ID | 20200121110256.12415-1-olivier.moysan@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: stm32-dfsdm: fix sleep in atomic context | expand |
On Tue, 21 Jan 2020 12:02:56 +0100 Olivier Moysan <olivier.moysan@st.com> wrote: > This commit fixes the error message: > "BUG: sleeping function called from invalid context at kernel/irq/chip.c" > Suppress the trigger irq handler. Make the buffer transfers directly > in DMA callback, instead. > Push buffers without timestamps, as timestamps are not supported > in DFSDM driver. > > Fixes: 11646e81d775 ("iio: adc: stm32-dfsdm: add support for buffer modes") > > Signed-off-by: Olivier Moysan <olivier.moysan@st.com> Applied to the fixes-togreg branch of iio.git and marked for stable. Thanks, Jonathan > --- > There is the same issue on STM32 ADC driver. > The solution for ADC driver has been already discussed in the thread > https://lkml.org/lkml/2019/3/30/171 > The current patch for STM32 DFSDM driver, bypasses the IIO IRQ trigger > handler, as proposed in this thread. > --- > drivers/iio/adc/stm32-dfsdm-adc.c | 43 +++++++------------------------ > 1 file changed, 10 insertions(+), 33 deletions(-) > > diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c > index 2aad2cda6943..76a60d93fe23 100644 > --- a/drivers/iio/adc/stm32-dfsdm-adc.c > +++ b/drivers/iio/adc/stm32-dfsdm-adc.c > @@ -842,31 +842,6 @@ static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc, > } > } > > -static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p) > -{ > - struct iio_poll_func *pf = p; > - struct iio_dev *indio_dev = pf->indio_dev; > - struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); > - int available = stm32_dfsdm_adc_dma_residue(adc); > - > - while (available >= indio_dev->scan_bytes) { > - s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; > - > - stm32_dfsdm_process_data(adc, buffer); > - > - iio_push_to_buffers_with_timestamp(indio_dev, buffer, > - pf->timestamp); > - available -= indio_dev->scan_bytes; > - adc->bufi += indio_dev->scan_bytes; > - if (adc->bufi >= adc->buf_sz) > - adc->bufi = 0; > - } > - > - iio_trigger_notify_done(indio_dev->trig); > - > - return IRQ_HANDLED; > -} > - > static void stm32_dfsdm_dma_buffer_done(void *data) > { > struct iio_dev *indio_dev = data; > @@ -874,11 +849,6 @@ static void stm32_dfsdm_dma_buffer_done(void *data) > int available = stm32_dfsdm_adc_dma_residue(adc); > size_t old_pos; > > - if (indio_dev->currentmode & INDIO_BUFFER_TRIGGERED) { > - iio_trigger_poll_chained(indio_dev->trig); > - return; > - } > - > /* > * FIXME: In Kernel interface does not support cyclic DMA buffer,and > * offers only an interface to push data samples per samples. > @@ -906,7 +876,15 @@ static void stm32_dfsdm_dma_buffer_done(void *data) > adc->bufi = 0; > old_pos = 0; > } > - /* regular iio buffer without trigger */ > + /* > + * In DMA mode the trigger services of IIO are not used > + * (e.g. no call to iio_trigger_poll). > + * Calling irq handler associated to the hardware trigger is not > + * relevant as the conversions have already been done. Data > + * transfers are performed directly in DMA callback instead. > + * This implementation avoids to call trigger irq handler that > + * may sleep, in an atomic context (DMA irq handler context). > + */ > if (adc->dev_data->type == DFSDM_IIO) > iio_push_to_buffers(indio_dev, buffer); > } > @@ -1536,8 +1514,7 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) > } > > ret = iio_triggered_buffer_setup(indio_dev, > - &iio_pollfunc_store_time, > - &stm32_dfsdm_adc_trigger_handler, > + &iio_pollfunc_store_time, NULL, > &stm32_dfsdm_buffer_setup_ops); > if (ret) { > stm32_dfsdm_dma_release(indio_dev);
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index 2aad2cda6943..76a60d93fe23 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -842,31 +842,6 @@ static inline void stm32_dfsdm_process_data(struct stm32_dfsdm_adc *adc, } } -static irqreturn_t stm32_dfsdm_adc_trigger_handler(int irq, void *p) -{ - struct iio_poll_func *pf = p; - struct iio_dev *indio_dev = pf->indio_dev; - struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - int available = stm32_dfsdm_adc_dma_residue(adc); - - while (available >= indio_dev->scan_bytes) { - s32 *buffer = (s32 *)&adc->rx_buf[adc->bufi]; - - stm32_dfsdm_process_data(adc, buffer); - - iio_push_to_buffers_with_timestamp(indio_dev, buffer, - pf->timestamp); - available -= indio_dev->scan_bytes; - adc->bufi += indio_dev->scan_bytes; - if (adc->bufi >= adc->buf_sz) - adc->bufi = 0; - } - - iio_trigger_notify_done(indio_dev->trig); - - return IRQ_HANDLED; -} - static void stm32_dfsdm_dma_buffer_done(void *data) { struct iio_dev *indio_dev = data; @@ -874,11 +849,6 @@ static void stm32_dfsdm_dma_buffer_done(void *data) int available = stm32_dfsdm_adc_dma_residue(adc); size_t old_pos; - if (indio_dev->currentmode & INDIO_BUFFER_TRIGGERED) { - iio_trigger_poll_chained(indio_dev->trig); - return; - } - /* * FIXME: In Kernel interface does not support cyclic DMA buffer,and * offers only an interface to push data samples per samples. @@ -906,7 +876,15 @@ static void stm32_dfsdm_dma_buffer_done(void *data) adc->bufi = 0; old_pos = 0; } - /* regular iio buffer without trigger */ + /* + * In DMA mode the trigger services of IIO are not used + * (e.g. no call to iio_trigger_poll). + * Calling irq handler associated to the hardware trigger is not + * relevant as the conversions have already been done. Data + * transfers are performed directly in DMA callback instead. + * This implementation avoids to call trigger irq handler that + * may sleep, in an atomic context (DMA irq handler context). + */ if (adc->dev_data->type == DFSDM_IIO) iio_push_to_buffers(indio_dev, buffer); } @@ -1536,8 +1514,7 @@ static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev) } ret = iio_triggered_buffer_setup(indio_dev, - &iio_pollfunc_store_time, - &stm32_dfsdm_adc_trigger_handler, + &iio_pollfunc_store_time, NULL, &stm32_dfsdm_buffer_setup_ops); if (ret) { stm32_dfsdm_dma_release(indio_dev);
This commit fixes the error message: "BUG: sleeping function called from invalid context at kernel/irq/chip.c" Suppress the trigger irq handler. Make the buffer transfers directly in DMA callback, instead. Push buffers without timestamps, as timestamps are not supported in DFSDM driver. Fixes: 11646e81d775 ("iio: adc: stm32-dfsdm: add support for buffer modes") Signed-off-by: Olivier Moysan <olivier.moysan@st.com> --- There is the same issue on STM32 ADC driver. The solution for ADC driver has been already discussed in the thread https://lkml.org/lkml/2019/3/30/171 The current patch for STM32 DFSDM driver, bypasses the IIO IRQ trigger handler, as proposed in this thread. --- drivers/iio/adc/stm32-dfsdm-adc.c | 43 +++++++------------------------ 1 file changed, 10 insertions(+), 33 deletions(-)