[PATCH] iio: adc: at91: Use dma_request_chan() instead dma_request_slave_channel()

[PATCH] iio: adc: at91: Use dma_request_chan() instead dma_request_slave_channel()

[Peter Ujfalusi]

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/at91-sama5d2_adc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index e1850f3d5cf3..a5c7771227d5 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -1444,10 +1444,10 @@ static void at91_adc_dma_init(struct platform_device *pdev)
 	if (st->dma_st.dma_chan)
 		return;
 
-	st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx");
-
-	if (!st->dma_st.dma_chan)  {
+	st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx");
+	if (IS_ERR(st->dma_st.dma_chan))  {
 		dev_info(&pdev->dev, "can't get DMA channel\n");
+		st->dma_st.dma_chan = NULL;
 		goto dma_exit;
 	}
 
-- 
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Re: [PATCH] iio: adc: at91: Use dma_request_chan() instead dma_request_slave_channel()

[Eugen.Hristev]

On 17.12.2019 09:50, 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>
> ---
>   drivers/iio/adc/at91-sama5d2_adc.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)

Hi Peter,

Thank you for the patch.
Nitpick : at91 is another driver (old one for different platforms), so 
can you please change the commit oneline to iio: adc: at91-sama5d2_adc: 
to not be confused about which driver is affected.

Thanks !
Eugen

> 
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index e1850f3d5cf3..a5c7771227d5 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -1444,10 +1444,10 @@ static void at91_adc_dma_init(struct platform_device *pdev)
>          if (st->dma_st.dma_chan)
>                  return;
> 
> -       st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx");
> -
> -       if (!st->dma_st.dma_chan)  {
> +       st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx");
> +       if (IS_ERR(st->dma_st.dma_chan))  {
>                  dev_info(&pdev->dev, "can't get DMA channel\n");
> +               st->dma_st.dma_chan = NULL;
>                  goto dma_exit;
>          }
> 
> --
> Peter
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
> 
> 

Re: [PATCH] iio: adc: at91: Use dma_request_chan() instead dma_request_slave_channel()

[Peter Ujfalusi]

Hi Eugen,

On 17/12/2019 9.59, Eugen.Hristev@microchip.com wrote:
> 
> 
> On 17.12.2019 09:50, 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>
>> ---
>>   drivers/iio/adc/at91-sama5d2_adc.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> Hi Peter,
> 
> Thank you for the patch.
> Nitpick : at91 is another driver (old one for different platforms), so 
> can you please change the commit oneline to iio: adc: at91-sama5d2_adc: 
> to not be confused about which driver is affected.

Sorry, just sent v2 with the correct subject prefix.
By mistake I looked at the git log of at91_adc.c and picked the wrong
prefix.

> 
> Thanks !
> Eugen
> 
>>
>> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
>> index e1850f3d5cf3..a5c7771227d5 100644
>> --- a/drivers/iio/adc/at91-sama5d2_adc.c
>> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
>> @@ -1444,10 +1444,10 @@ static void at91_adc_dma_init(struct platform_device *pdev)
>>          if (st->dma_st.dma_chan)
>>                  return;
>>
>> -       st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx");
>> -
>> -       if (!st->dma_st.dma_chan)  {
>> +       st->dma_st.dma_chan = dma_request_chan(&pdev->dev, "rx");
>> +       if (IS_ERR(st->dma_st.dma_chan))  {
>>                  dev_info(&pdev->dev, "can't get DMA channel\n");
>> +               st->dma_st.dma_chan = NULL;
>>                  goto dma_exit;
>>          }
>>
>> --
>> Peter
>>
>> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
>> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>>

- Péter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki