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iio: adc: stm32-dfsdm: fix sleep in atomic context 

commit e19ac9d9a9 upstream.

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: 11646e81d7 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Olivier Moysan 2020-01-21 12:02:56 +01:00 committed by Greg Kroah-Hartman
parent a79f53a2f5
commit 4d71a4f761
1 changed files with 10 additions and 33 deletions
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43
drivers/iio/adc/stm32-dfsdm-adc.c
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@ -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);
}
@ -1517,8 +1495,7 @@ 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);