2020-11-05 14:33:12

by Olivier Moysan

Subject: [PATCH] iio: adc: stm32-adc: dma transfers cleanup

- Remove processing related to DMA in irq handler as this
data transfer is managed directly in DMA callback.
- Update comment in stm32_adc_set_watermark() function.

Signed-off-by: Olivier Moysan <[email protected]>
---
drivers/iio/adc/stm32-adc.c | 29 ++++++-----------------------
1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index b3f31f147347..08be826f1462 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -1310,7 +1310,7 @@ static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
* dma cyclic transfers are used, buffer is split into two periods.
* There should be :
* - always one buffer (period) dma is working on
- * - one buffer (period) driver can push with iio_trigger_poll().
+ * - one buffer (period) driver can push data.
*/
watermark = min(watermark, val * (unsigned)(sizeof(u16)));
adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
@@ -1573,31 +1573,14 @@ static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)

dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);

- if (!adc->dma_chan) {
- /* reset buffer index */
- adc->bufi = 0;
- iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
- pf->timestamp);
- } else {
- int residue = stm32_adc_dma_residue(adc);
-
- while (residue >= indio_dev->scan_bytes) {
- u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
-
- iio_push_to_buffers_with_timestamp(indio_dev, buffer,
- pf->timestamp);
- residue -= indio_dev->scan_bytes;
- adc->bufi += indio_dev->scan_bytes;
- if (adc->bufi >= adc->rx_buf_sz)
- adc->bufi = 0;
- }
- }
-
+ /* reset buffer index */
+ adc->bufi = 0;
+ iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
+ pf->timestamp);
iio_trigger_notify_done(indio_dev->trig);

/* re-enable eoc irq */
- if (!adc->dma_chan)
- stm32_adc_conv_irq_enable(adc);
+ stm32_adc_conv_irq_enable(adc);

return IRQ_HANDLED;
}
--
2.17.1

2020-11-05 17:43:10

by Fabrice Gasnier

Subject: Re: [PATCH] iio: adc: stm32-adc: dma transfers cleanup

On 11/5/20 3:29 PM, Olivier Moysan wrote:
> - Remove processing related to DMA in irq handler as this
> data transfer is managed directly in DMA callback.
> - Update comment in stm32_adc_set_watermark() function.
>
> Signed-off-by: Olivier Moysan <[email protected]>

Hi Olivier,

Reviewed-by: Fabrice Gasnier <[email protected]>

Thanks,
Fabrice
> ---
> drivers/iio/adc/stm32-adc.c | 29 ++++++-----------------------
> 1 file changed, 6 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index b3f31f147347..08be826f1462 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -1310,7 +1310,7 @@ static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
> * dma cyclic transfers are used, buffer is split into two periods.
> * There should be :
> * - always one buffer (period) dma is working on
> - * - one buffer (period) driver can push with iio_trigger_poll().
> + * - one buffer (period) driver can push data.
> */
> watermark = min(watermark, val * (unsigned)(sizeof(u16)));
> adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
> @@ -1573,31 +1573,14 @@ static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
>
> dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
>
> - if (!adc->dma_chan) {
> - /* reset buffer index */
> - adc->bufi = 0;
> - iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
> - pf->timestamp);
> - } else {
> - int residue = stm32_adc_dma_residue(adc);
> -
> - while (residue >= indio_dev->scan_bytes) {
> - u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
> -
> - iio_push_to_buffers_with_timestamp(indio_dev, buffer,
> - pf->timestamp);
> - residue -= indio_dev->scan_bytes;
> - adc->bufi += indio_dev->scan_bytes;
> - if (adc->bufi >= adc->rx_buf_sz)
> - adc->bufi = 0;
> - }
> - }
> -
> + /* reset buffer index */
> + adc->bufi = 0;
> + iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
> + pf->timestamp);
> iio_trigger_notify_done(indio_dev->trig);
>
> /* re-enable eoc irq */
> - if (!adc->dma_chan)
> - stm32_adc_conv_irq_enable(adc);
> + stm32_adc_conv_irq_enable(adc);
>
> return IRQ_HANDLED;
> }
>

2020-11-08 15:34:22

by Jonathan Cameron

Subject: Re: [PATCH] iio: adc: stm32-adc: dma transfers cleanup

On Thu, 5 Nov 2020 18:38:27 +0100
Fabrice Gasnier <[email protected]> wrote:

> On 11/5/20 3:29 PM, Olivier Moysan wrote:
> > - Remove processing related to DMA in irq handler as this
> > data transfer is managed directly in DMA callback.
> > - Update comment in stm32_adc_set_watermark() function.
> >
> > Signed-off-by: Olivier Moysan <[email protected]>
>
> Hi Olivier,
>
> Reviewed-by: Fabrice Gasnier <[email protected]>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to poke at it.

Thanks,

Jonathan

>
> Thanks,
> Fabrice
> > ---
> > drivers/iio/adc/stm32-adc.c | 29 ++++++-----------------------
> > 1 file changed, 6 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> > index b3f31f147347..08be826f1462 100644
> > --- a/drivers/iio/adc/stm32-adc.c
> > +++ b/drivers/iio/adc/stm32-adc.c
> > @@ -1310,7 +1310,7 @@ static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
> > * dma cyclic transfers are used, buffer is split into two periods.
> > * There should be :
> > * - always one buffer (period) dma is working on
> > - * - one buffer (period) driver can push with iio_trigger_poll().
> > + * - one buffer (period) driver can push data.
> > */
> > watermark = min(watermark, val * (unsigned)(sizeof(u16)));
> > adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
> > @@ -1573,31 +1573,14 @@ static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
> >
> > dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
> >
> > - if (!adc->dma_chan) {
> > - /* reset buffer index */
> > - adc->bufi = 0;
> > - iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
> > - pf->timestamp);
> > - } else {
> > - int residue = stm32_adc_dma_residue(adc);
> > -
> > - while (residue >= indio_dev->scan_bytes) {
> > - u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
> > -
> > - iio_push_to_buffers_with_timestamp(indio_dev, buffer,
> > - pf->timestamp);
> > - residue -= indio_dev->scan_bytes;
> > - adc->bufi += indio_dev->scan_bytes;
> > - if (adc->bufi >= adc->rx_buf_sz)
> > - adc->bufi = 0;
> > - }
> > - }
> > -
> > + /* reset buffer index */
> > + adc->bufi = 0;
> > + iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
> > + pf->timestamp);
> > iio_trigger_notify_done(indio_dev->trig);
> >
> > /* re-enable eoc irq */
> > - if (!adc->dma_chan)
> > - stm32_adc_conv_irq_enable(adc);
> > + stm32_adc_conv_irq_enable(adc);
> >
> > return IRQ_HANDLED;
> > }
> >