| Message ID | 1572015860-8931-1-git-send-email-fabrice.gasnier@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: stm32-adc: fix stopping dma | expand |
On Fri, 25 Oct 2019 17:04:20 +0200 Fabrice Gasnier <fabrice.gasnier@st.com> wrote: > There maybe a race when using dmaengine_terminate_all(). The predisable > routine may call iio_triggered_buffer_predisable() prior to a pending DMA > callback. > Adopt dmaengine_terminate_sync() to ensure there's no pending DMA request > before calling iio_triggered_buffer_predisable(). > > Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Applied to the fixes-togreg branch of iio.git and marked for stable. I'm guessing this is not something that has been observed in practice, but seems like a safe fix anyway to backport. Thanks, Jonathan > --- > drivers/iio/adc/stm32-adc.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index 663f8a5..73aee59 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -1399,7 +1399,7 @@ static int stm32_adc_dma_start(struct iio_dev *indio_dev) > cookie = dmaengine_submit(desc); > ret = dma_submit_error(cookie); > if (ret) { > - dmaengine_terminate_all(adc->dma_chan); > + dmaengine_terminate_sync(adc->dma_chan); > return ret; > } > > @@ -1477,7 +1477,7 @@ static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev) > stm32_adc_conv_irq_disable(adc); > > if (adc->dma_chan) > - dmaengine_terminate_all(adc->dma_chan); > + dmaengine_terminate_sync(adc->dma_chan); > > if (stm32_adc_set_trig(indio_dev, NULL)) > dev_err(&indio_dev->dev, "Can't clear trigger\n");
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c index 663f8a5..73aee59 100644 --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -1399,7 +1399,7 @@ static int stm32_adc_dma_start(struct iio_dev *indio_dev) cookie = dmaengine_submit(desc); ret = dma_submit_error(cookie); if (ret) { - dmaengine_terminate_all(adc->dma_chan); + dmaengine_terminate_sync(adc->dma_chan); return ret; } @@ -1477,7 +1477,7 @@ static void __stm32_adc_buffer_predisable(struct iio_dev *indio_dev) stm32_adc_conv_irq_disable(adc); if (adc->dma_chan) - dmaengine_terminate_all(adc->dma_chan); + dmaengine_terminate_sync(adc->dma_chan); if (stm32_adc_set_trig(indio_dev, NULL)) dev_err(&indio_dev->dev, "Can't clear trigger\n");
There maybe a race when using dmaengine_terminate_all(). The predisable routine may call iio_triggered_buffer_predisable() prior to a pending DMA callback. Adopt dmaengine_terminate_sync() to ensure there's no pending DMA request before calling iio_triggered_buffer_predisable(). Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> --- drivers/iio/adc/stm32-adc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)