* [PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()
@ 2019-12-17 7:52 Peter Ujfalusi
2019-12-23 15:45 ` Jonathan Cameron
0 siblings, 1 reply; 3+ messages in thread
From: Peter Ujfalusi @ 2019-12-17 7:52 UTC (permalink / raw)
To: jic23, mcoquelin.stm32, alexandre.torgue
Cc: linux-iio, vkoul, linux-kernel, linux-arm-kernel, linux-stm32
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(-)
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
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^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()
2019-12-17 7:52 [PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel() Peter Ujfalusi
@ 2019-12-23 15:45 ` Jonathan Cameron
2019-12-23 22:00 ` Peter Ujfalusi
0 siblings, 1 reply; 3+ messages in thread
From: Jonathan Cameron @ 2019-12-23 15:45 UTC (permalink / raw)
To: Peter Ujfalusi
Cc: alexandre.torgue, linux-iio, linux-kernel, vkoul, mcoquelin.stm32,
linux-stm32, linux-arm-kernel
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,
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()
2019-12-23 15:45 ` Jonathan Cameron
@ 2019-12-23 22:00 ` Peter Ujfalusi
0 siblings, 0 replies; 3+ messages in thread
From: Peter Ujfalusi @ 2019-12-23 22:00 UTC (permalink / raw)
To: Jonathan Cameron
Cc: alexandre.torgue, linux-iio, linux-kernel, vkoul, mcoquelin.stm32,
linux-stm32, linux-arm-kernel
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
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^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-12-23 21:59 UTC | newest]
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2019-12-17 7:52 [PATCH] iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel() Peter Ujfalusi
2019-12-23 15:45 ` Jonathan Cameron
2019-12-23 22:00 ` Peter Ujfalusi
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