Messages in this thread | | | Date | Mon, 23 Dec 2019 15:50:01 +0000 | From | Jonathan Cameron <> | Subject | Re: [PATCH v2] iio: adc: at91-sama5d2_adc: Use dma_request_chan() instead dma_request_slave_channel() |
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On Tue, 17 Dec 2019 12:31:00 +0200 Peter Ujfalusi <peter.ujfalusi@ti.com> 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. Unfortunately that doesn't seem to be true. The function in question returns void...
And for that matter is called only from the set_watermark callback which doesn't run at probe time.
So if we were to get a deferred response at runtime there isn't a whole lot we could do with it.
Jonathan
> > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > --- > Hi, > > Changes since v1: > - Subject prefix is corrected to "iio: adc: at91-sama5d2_adc:" > > Regards, > Peter > > drivers/iio/adc/at91-sama5d2_adc.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c > index e1850f3d5cf3..a5c7771227d5 100644 > --- a/drivers/iio/adc/at91-sama5d2_adc.c > +++ b/drivers/iio/adc/at91-sama5d2_adc.c > @@ -1444,10 +1444,10 @@ static void at91_adc_dma_init(struct platform_device *pdev) > if (st->dma_st.dma_chan) > return; > > - st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx"); > - > - if (!st->dma_st.dma_chan) { > + st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx"); > + if (IS_ERR(st->dma_st.dma_chan)) { > dev_info(&pdev->dev, "can't get DMA channel\n"); > + st->dma_st.dma_chan = NULL; > goto dma_exit; > } >
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