Messages in this thread Patch in this message |  | | From | Peter Ujfalusi <> | Subject | [PATCH v2] iio: adc: stm32-adc: Use dma_request_chan() instead dma_request_slave_channel() | Date | Tue, 7 Jan 2020 13:41:25 +0200 |
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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(-)
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, -- Peter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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