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@xxxxxx>
---
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);
--
2.17.1
