| Message ID | 20191217075221.23895-1-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel() | expand |
On Tue, 17 Dec 2019 09:52:21 +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. > > Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> I don't think this one goes far enough. One of the paths does: /* Optionally request DMA */ if (stm32_dfsdm_dma_request(indio_dev)) { dev_dbg(&indio_dev->dev, "No DMA support\n"); return 0; } That needs specific handling for deferred probing. > --- > drivers/iio/adc/stm32-dfsdm-adc.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c > index e493242c266e..3aac1a21f9d0 100644 > --- a/drivers/iio/adc/stm32-dfsdm-adc.c > +++ b/drivers/iio/adc/stm32-dfsdm-adc.c > @@ -1383,9 +1383,9 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev) > { > struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); > > - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); > - if (!adc->dma_chan) > - return -EINVAL; > + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); > + if (IS_ERR(adc->dma_chan)) > + return PTR_ERR(adc->dma_chan); > > adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, > DFSDM_DMA_BUFFER_SIZE,
Hi Jonathan, On 12/23/19 5:45 PM, Jonathan Cameron wrote: > On Tue, 17 Dec 2019 09:52:21 +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. >> >> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> > I don't think this one goes far enough. > > One of the paths does: > > /* Optionally request DMA */ > if (stm32_dfsdm_dma_request(indio_dev)) { > dev_dbg(&indio_dev->dev, "No DMA support\n"); > return 0; > } > > That needs specific handling for deferred probing. Right, I have checked the stm32_dfsdm_audio_init() path, via that the error is propagated correctly. I'll send an update next year ;) > >> --- >> drivers/iio/adc/stm32-dfsdm-adc.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c >> index e493242c266e..3aac1a21f9d0 100644 >> --- a/drivers/iio/adc/stm32-dfsdm-adc.c >> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c >> @@ -1383,9 +1383,9 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev) >> { >> struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); >> >> - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); >> - if (!adc->dma_chan) >> - return -EINVAL; >> + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); >> + if (IS_ERR(adc->dma_chan)) >> + return PTR_ERR(adc->dma_chan); >> >> adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, >> DFSDM_DMA_BUFFER_SIZE, > - Peter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c index e493242c266e..3aac1a21f9d0 100644 --- a/drivers/iio/adc/stm32-dfsdm-adc.c +++ b/drivers/iio/adc/stm32-dfsdm-adc.c @@ -1383,9 +1383,9 @@ static int stm32_dfsdm_dma_request(struct iio_dev *indio_dev) { struct stm32_dfsdm_adc *adc = iio_priv(indio_dev); - adc->dma_chan = dma_request_slave_channel(&indio_dev->dev, "rx"); - if (!adc->dma_chan) - return -EINVAL; + adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx"); + if (IS_ERR(adc->dma_chan)) + return PTR_ERR(adc->dma_chan); adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, DFSDM_DMA_BUFFER_SIZE,
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> --- drivers/iio/adc/stm32-dfsdm-adc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)