This is a note to let you know that I've just added the patch titled
iio: adc: stm32-dfsdm: fix sleep in atomic context
to my staging git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git in the staging-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From e19ac9d9a978f8238a85a28ed624094a497d5ae6 Mon Sep 17 00:00:00 2001
From: Olivier Moysan olivier.moysan@st.com Date: Tue, 21 Jan 2020 12:02:56 +0100 Subject: iio: adc: stm32-dfsdm: fix sleep in atomic context
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 Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- 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);