| Message ID | 20200107114125.6095-1-peter.ujfalusi@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() | expand |
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, >
Hi Fabrice, On 07/01/2020 19.15, Fabrice Gasnier wrote: > 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: Thanks, I'll take your suggested update and send v3. > 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 */ Makes more sense in the context. > >> + adc->dma_chan = NULL; >> return 0; >> + } >> >> adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, >> STM32_DMA_BUFFER_SIZE, >> - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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 */ + adc->dma_chan = NULL; return 0; + } adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, STM32_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> --- Hi, Changes since v1: - Fall back to IRQ mode only in case of ENODEV Regards, Peter drivers/iio/adc/stm32-adc.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)