Messages in this thread |  | | Subject | Re: [PATCH v2] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() | From | Fabrice Gasnier <> | Date | Tue, 7 Jan 2020 18:15:49 +0100 |
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On 1/7/20 12:41 PM, Peter Ujfalusi wrote: > dma_request_slave_channel() is a wrapper on top of dma_request_chan() > eating up the error code. > > By using dma_request_chan() directly the driver can support deferred > probing against DMA. > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > --- > Hi, > > Changes since v1: > - Fall back to IRQ mode only in case of ENODEV > > Regards, > Peter
Hi Peter,
Thanks for the patch,
In case you send another version... I've just a minor suggestion regarding the comment (see after). Apart from that, you can add my:
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Best Regards, Fabrice
> > drivers/iio/adc/stm32-adc.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > index 3b291d72701c..df5f5d61f9f9 100644 > --- a/drivers/iio/adc/stm32-adc.c > +++ b/drivers/iio/adc/stm32-adc.c > @@ -1746,9 +1746,21 @@ static int stm32_adc_dma_request(struct iio_dev *indio_dev) > struct dma_slave_config config; > int ret; > > - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); > - if (!adc->dma_chan) > + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); > + if (IS_ERR(adc->dma_chan)) { > + ret = PTR_ERR(adc->dma_chan); > + if (ret != -ENODEV) { > + if (ret != -EPROBE_DEFER) > + dev_err(&indio_dev->dev, > + "DMA channel request failed with %d\n", > + ret); > + return ret; > + } > + > + /* Ignore errors to fall back to IRQ mode */ ^ error alternate suggestion: /* DMA is optional: fall back to IRQ mode */
> + adc->dma_chan = NULL; > return 0; > + } > > adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, > STM32_DMA_BUFFER_SIZE, >
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