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@xxxxxx>
>> ---
>> 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@xxxxxx>
>
> 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
