media: stm32-dcmi: Use dma_request_chan() instead dma_request_slave_channel()
diff mbox series

Message ID 20191217104135.23554-1-peter.ujfalusi@ti.com
State New
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Series
  • media: stm32-dcmi: Use dma_request_chan() instead dma_request_slave_channel()
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Commit Message

Peter Ujfalusi Dec. 17, 2019, 10:41 a.m. UTC
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/media/platform/stm32/stm32-dcmi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Hugues FRUCHET Dec. 18, 2019, 10:52 a.m. UTC | #1
Thanks for patching Peter,

No regression observed on my side.

Acked-by: Hugues Fruchet <hugues.fruchet@st.com>

Best regards,
Hugues.

On 12/17/19 11:41 AM, 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/media/platform/stm32/stm32-dcmi.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index 9392e3409fba..55351872b0c7 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -1910,10 +1910,10 @@ static int dcmi_probe(struct platform_device *pdev)
>   		return PTR_ERR(mclk);
>   	}
>   
> -	chan = dma_request_slave_channel(&pdev->dev, "tx");
> -	if (!chan) {
> +	chan = dma_request_chan(&pdev->dev, "tx");
> +	if (IS_ERR(chan)) {
>   		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
> -		return -EPROBE_DEFER;
> +		return PTR_ERR(chan);
>   	}
>   
>   	spin_lock_init(&dcmi->irqlock);
>
Hugues FRUCHET Jan. 7, 2020, 9:46 a.m. UTC | #2
Hi Peter,

If not too late, could you change trace to only trig error trace when
error is not "probe defered" ? See below:

-	chan = dma_request_slave_channel(&pdev->dev, "tx");
-	if (!chan) {
-		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
-		return -EPROBE_DEFER;
+	chan = dma_request_chan(&pdev->dev, "tx");
+	if (IS_ERR(chan)) {
+		if (PTR_ERR(chan) != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Unable to request DMA channel\n");
+		return PTR_ERR(chan);


Best regards,
Hugues.

On 12/18/19 11:52 AM, Hugues FRUCHET wrote:
> Thanks for patching Peter,
> 
> No regression observed on my side.
> 
> Acked-by: Hugues Fruchet <hugues.fruchet@st.com>
> 
> Best regards,
> Hugues.
> 
> On 12/17/19 11:41 AM, 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/media/platform/stm32/stm32-dcmi.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c 
>> b/drivers/media/platform/stm32/stm32-dcmi.c
>> index 9392e3409fba..55351872b0c7 100644
>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>> @@ -1910,10 +1910,10 @@ static int dcmi_probe(struct platform_device 
>> *pdev)
>>           return PTR_ERR(mclk);
>>       }
>> -    chan = dma_request_slave_channel(&pdev->dev, "tx");
>> -    if (!chan) {
>> +    chan = dma_request_chan(&pdev->dev, "tx");
>> +    if (IS_ERR(chan)) {
>>           dev_info(&pdev->dev, "Unable to request DMA channel, defer 
>> probing\n");
>> -        return -EPROBE_DEFER;
>> +        return PTR_ERR(chan);
>>       }
>>       spin_lock_init(&dcmi->irqlock);
>>
Peter Ujfalusi Jan. 7, 2020, 10:38 a.m. UTC | #3
Hi Hugues,

On 07/01/2020 11.46, Hugues FRUCHET wrote:
> Hi Peter,
> 
> If not too late, could you change trace to only trig error trace when
> error is not "probe defered" ? See below:
> 
> -	chan = dma_request_slave_channel(&pdev->dev, "tx");
> -	if (!chan) {
> -		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
> -		return -EPROBE_DEFER;
> +	chan = dma_request_chan(&pdev->dev, "tx");
> +	if (IS_ERR(chan)) {
> +		if (PTR_ERR(chan) != -EPROBE_DEFER)
> +			dev_err(&pdev->dev, "Unable to request DMA channel\n");
> +		return PTR_ERR(chan);

Sure, I don't know how I missed it.

Regards,
- Péter

> 
> Best regards,
> Hugues.
> 
> On 12/18/19 11:52 AM, Hugues FRUCHET wrote:
>> Thanks for patching Peter,
>>
>> No regression observed on my side.
>>
>> Acked-by: Hugues Fruchet <hugues.fruchet@st.com>
>>
>> Best regards,
>> Hugues.
>>
>> On 12/17/19 11:41 AM, 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/media/platform/stm32/stm32-dcmi.c | 6 +++---
>>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c 
>>> b/drivers/media/platform/stm32/stm32-dcmi.c
>>> index 9392e3409fba..55351872b0c7 100644
>>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>>> @@ -1910,10 +1910,10 @@ static int dcmi_probe(struct platform_device 
>>> *pdev)
>>>           return PTR_ERR(mclk);
>>>       }
>>> -    chan = dma_request_slave_channel(&pdev->dev, "tx");
>>> -    if (!chan) {
>>> +    chan = dma_request_chan(&pdev->dev, "tx");
>>> +    if (IS_ERR(chan)) {
>>>           dev_info(&pdev->dev, "Unable to request DMA channel, defer 
>>> probing\n");
>>> -        return -EPROBE_DEFER;
>>> +        return PTR_ERR(chan);
>>>       }
>>>       spin_lock_init(&dcmi->irqlock);
>> >


Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
Hugues FRUCHET Jan. 7, 2020, 11:08 a.m. UTC | #4
Y're welcome.

On 1/7/20 11:38 AM, Peter Ujfalusi wrote:
> Hi Hugues,
> 
> On 07/01/2020 11.46, Hugues FRUCHET wrote:
>> Hi Peter,
>>
>> If not too late, could you change trace to only trig error trace when
>> error is not "probe defered" ? See below:
>>
>> -	chan = dma_request_slave_channel(&pdev->dev, "tx");
>> -	if (!chan) {
>> -		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
>> -		return -EPROBE_DEFER;
>> +	chan = dma_request_chan(&pdev->dev, "tx");
>> +	if (IS_ERR(chan)) {
>> +		if (PTR_ERR(chan) != -EPROBE_DEFER)
>> +			dev_err(&pdev->dev, "Unable to request DMA channel\n");
>> +		return PTR_ERR(chan);
> 
> Sure, I don't know how I missed it.
> 
> Regards,
> - Péter
> 
>>
>> Best regards,
>> Hugues.
>>
>> On 12/18/19 11:52 AM, Hugues FRUCHET wrote:
>>> Thanks for patching Peter,
>>>
>>> No regression observed on my side.
>>>
>>> Acked-by: Hugues Fruchet <hugues.fruchet@st.com>
>>>
>>> Best regards,
>>> Hugues.
>>>
>>> On 12/17/19 11:41 AM, 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/media/platform/stm32/stm32-dcmi.c | 6 +++---
>>>>    1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c
>>>> b/drivers/media/platform/stm32/stm32-dcmi.c
>>>> index 9392e3409fba..55351872b0c7 100644
>>>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>>>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>>>> @@ -1910,10 +1910,10 @@ static int dcmi_probe(struct platform_device
>>>> *pdev)
>>>>            return PTR_ERR(mclk);
>>>>        }
>>>> -    chan = dma_request_slave_channel(&pdev->dev, "tx");
>>>> -    if (!chan) {
>>>> +    chan = dma_request_chan(&pdev->dev, "tx");
>>>> +    if (IS_ERR(chan)) {
>>>>            dev_info(&pdev->dev, "Unable to request DMA channel, defer
>>>> probing\n");
>>>> -        return -EPROBE_DEFER;
>>>> +        return PTR_ERR(chan);
>>>>        }
>>>>        spin_lock_init(&dcmi->irqlock);
>>>>
> 
> 
> Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
> Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
>

Patch
diff mbox series

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 9392e3409fba..55351872b0c7 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -1910,10 +1910,10 @@  static int dcmi_probe(struct platform_device *pdev)
 		return PTR_ERR(mclk);
 	}
 
-	chan = dma_request_slave_channel(&pdev->dev, "tx");
-	if (!chan) {
+	chan = dma_request_chan(&pdev->dev, "tx");
+	if (IS_ERR(chan)) {
 		dev_info(&pdev->dev, "Unable to request DMA channel, defer probing\n");
-		return -EPROBE_DEFER;
+		return PTR_ERR(chan);
 	}
 
 	spin_lock_init(&dcmi->irqlock);