iio: adc: stm32-adc: fix stopping dma

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>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 663f8a5012d64123b06a646887c4c75a5f9860e1..73aee5949b6b3cc17cd3b1543a33a23f29c188b3 100644 (file)
--- 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");