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authorEugen Hristev <eugen.hristev@microchip.com>2020-09-23 15:17:48 +0300
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2020-09-29 17:50:35 +0100
commit1a198794451449113fa86994ed491d6986802c23 (patch)
treef8b8a9753897319fc54b70f44e32a60a71d5023d /drivers/iio
parentb8a533f3c24b3b8f1fdbefc5ada6a7d5733d63e6 (diff)
iio: adc: at91-sama5d2_adc: fix DMA conversion crash
After the move of the postenable code to preenable, the DMA start was done before the DMA init, which is not correct. The DMA is initialized in set_watermark. Because of this, we need to call the DMA start functions in set_watermark, after the DMA init, instead of preenable hook, when the DMA is not properly setup yet. Fixes: f3c034f61775 ("iio: at91-sama5d2_adc: adjust iio_triggered_buffer_{predisable,postenable} positions") Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> Link: https://lore.kernel.org/r/20200923121748.49384-1-eugen.hristev@microchip.com Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/adc/at91-sama5d2_adc.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index ad7d9819f83c..b917a4714a9c 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -884,7 +884,7 @@ static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
AT91_SAMA5D2_MAX_CHAN_IDX + 1);
}
-static int at91_adc_buffer_preenable(struct iio_dev *indio_dev)
+static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
{
int ret;
u8 bit;
@@ -901,7 +901,7 @@ static int at91_adc_buffer_preenable(struct iio_dev *indio_dev)
/* we continue with the triggered buffer */
ret = at91_adc_dma_start(indio_dev);
if (ret) {
- dev_err(&indio_dev->dev, "buffer postenable failed\n");
+ dev_err(&indio_dev->dev, "buffer prepare failed\n");
return ret;
}
@@ -989,7 +989,6 @@ static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
}
static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
- .preenable = &at91_adc_buffer_preenable,
.postdisable = &at91_adc_buffer_postdisable,
};
@@ -1563,6 +1562,7 @@ static void at91_adc_dma_disable(struct platform_device *pdev)
static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
{
struct at91_adc_state *st = iio_priv(indio_dev);
+ int ret;
if (val > AT91_HWFIFO_MAX_SIZE)
return -EINVAL;
@@ -1586,7 +1586,15 @@ static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
else if (val > 1)
at91_adc_dma_init(to_platform_device(&indio_dev->dev));
- return 0;
+ /*
+ * We can start the DMA only after setting the watermark and
+ * having the DMA initialization completed
+ */
+ ret = at91_adc_buffer_prepare(indio_dev);
+ if (ret)
+ at91_adc_dma_disable(to_platform_device(&indio_dev->dev));
+
+ return ret;
}
static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,