[PATCH] media: xilinx: Use dma_request_chan() instead dma_request_slave_channel()

[PATCH] media: xilinx: 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/media/platform/xilinx/xilinx-dma.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
index b211380a11f2..9ce515ff9c0a 100644
--- a/drivers/media/platform/xilinx/xilinx-dma.c
+++ b/drivers/media/platform/xilinx/xilinx-dma.c
@@ -725,10 +725,10 @@ int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
 
 	/* ... and the DMA channel. */
 	snprintf(name, sizeof(name), "port%u", port);
-	dma->dma = dma_request_slave_channel(dma->xdev->dev, name);
-	if (dma->dma == NULL) {
+	dma->dma = dma_request_chan(dma->xdev->dev, name);
+	if (IS_ERR(dma->dma)) {
 		dev_err(dma->xdev->dev, "no VDMA channel found\n");
-		ret = -ENODEV;
+		ret = PTR_ERR(dma->dma);
 		goto error;
 	}
 
-- 
Peter

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


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Re: [PATCH] media: xilinx: Use dma_request_chan() instead dma_request_slave_channel()

[Laurent Pinchart]

Hi Peter,

Thank you for the patch.

On Tue, Dec 17, 2019 at 12:42:35PM +0200, 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>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Vinod, could you please pick this up ?

> ---
>  drivers/media/platform/xilinx/xilinx-dma.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> index b211380a11f2..9ce515ff9c0a 100644
> --- a/drivers/media/platform/xilinx/xilinx-dma.c
> +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> @@ -725,10 +725,10 @@ int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
>  
>  	/* ... and the DMA channel. */
>  	snprintf(name, sizeof(name), "port%u", port);
> -	dma->dma = dma_request_slave_channel(dma->xdev->dev, name);
> -	if (dma->dma == NULL) {
> +	dma->dma = dma_request_chan(dma->xdev->dev, name);
> +	if (IS_ERR(dma->dma)) {
>  		dev_err(dma->xdev->dev, "no VDMA channel found\n");
> -		ret = -ENODEV;
> +		ret = PTR_ERR(dma->dma);
>  		goto error;
>  	}
>  

-- 
Regards,

Laurent Pinchart

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Re: [PATCH] media: xilinx: Use dma_request_chan() instead dma_request_slave_channel()

[Laurent Pinchart]

Hello again,

On Thu, Jan 09, 2020 at 06:48:47PM +0200, Laurent Pinchart wrote:
> On Tue, Dec 17, 2019 at 12:42:35PM +0200, 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>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Vinod, could you please pick this up ?

I spoke too fast.

> > ---
> >  drivers/media/platform/xilinx/xilinx-dma.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> > index b211380a11f2..9ce515ff9c0a 100644
> > --- a/drivers/media/platform/xilinx/xilinx-dma.c
> > +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> > @@ -725,10 +725,10 @@ int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
> >  
> >  	/* ... and the DMA channel. */
> >  	snprintf(name, sizeof(name), "port%u", port);
> > -	dma->dma = dma_request_slave_channel(dma->xdev->dev, name);
> > -	if (dma->dma == NULL) {
> > +	dma->dma = dma_request_chan(dma->xdev->dev, name);
> > +	if (IS_ERR(dma->dma)) {
> >  		dev_err(dma->xdev->dev, "no VDMA channel found\n");
> > -		ret = -ENODEV;
> > +		ret = PTR_ERR(dma->dma);
> >  		goto error;

At the error label, we have

error:
	xvip_dma_cleanup(dma);
	return ret;

and xvip_dma_cleanup() contains

	if (dma->dma)
		dma_release_channel(dma->dma);

You need to turn this into

	if (!IS_ERR_OR_NULL(dma->dma))

or add a

		dma->dma = NULL;

in the error case in xvip_dma_init().

> >  	}
> >  

-- 
Regards,

Laurent Pinchart

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Re: [PATCH] media: xilinx: Use dma_request_chan() instead dma_request_slave_channel()

[Peter Ujfalusi]

On 09/01/2020 18.53, Laurent Pinchart wrote:
> Hello again,
> 
> On Thu, Jan 09, 2020 at 06:48:47PM +0200, Laurent Pinchart wrote:
>> On Tue, Dec 17, 2019 at 12:42:35PM +0200, 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>
>>
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>
>> Vinod, could you please pick this up ?
> 
> I spoke too fast.
> 
>>> ---
>>>  drivers/media/platform/xilinx/xilinx-dma.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
>>> index b211380a11f2..9ce515ff9c0a 100644
>>> --- a/drivers/media/platform/xilinx/xilinx-dma.c
>>> +++ b/drivers/media/platform/xilinx/xilinx-dma.c
>>> @@ -725,10 +725,10 @@ int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
>>>  
>>>  	/* ... and the DMA channel. */
>>>  	snprintf(name, sizeof(name), "port%u", port);
>>> -	dma->dma = dma_request_slave_channel(dma->xdev->dev, name);
>>> -	if (dma->dma == NULL) {
>>> +	dma->dma = dma_request_chan(dma->xdev->dev, name);
>>> +	if (IS_ERR(dma->dma)) {
>>>  		dev_err(dma->xdev->dev, "no VDMA channel found\n");

and print this only in case of !EPROBE_DEFER

>>> -		ret = -ENODEV;
>>> +		ret = PTR_ERR(dma->dma);
>>>  		goto error;
> 
> At the error label, we have
> 
> error:
> 	xvip_dma_cleanup(dma);
> 	return ret;
> 
> and xvip_dma_cleanup() contains
> 
> 	if (dma->dma)
> 		dma_release_channel(dma->dma);
> 
> You need to turn this into
> 
> 	if (!IS_ERR_OR_NULL(dma->dma))

I generally try to avoid IS_ERR_OR_NULL()

> 
> or add a
> 
> 		dma->dma = NULL;

But in this case I think it looks better that way.

> 
> in the error case in xvip_dma_init().
> 
>>>  	}
>>>  
> 

- Péter

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

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