media: pt3: Use dma_set_mask_and_coherent() and simplify code

[PATCH] media: pt3: Use dma_set_mask_and_coherent() and simplify code

Posted by Christophe JAILLET 4 years, 6 months ago

Use dma_set_mask_and_coherent() instead of unrolling it with some
dma_set_mask()+dma_set_coherent_mask().

Moreover, as stated in [1], dma_set_mask() with a 64-bit mask will never
fail if dev->dma_mask is non-NULL.
So, if it fails, the 32 bits case will also fail for the same reason.

Simplify code and remove some dead code accordingly.

[1]: https://lkml.org/lkml/2021/6/7/398

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/media/pci/pt3/pt3.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/media/pci/pt3/pt3.c b/drivers/media/pci/pt3/pt3.c
index 0d51bdf01f43..11f26cac0abc 100644
--- a/drivers/media/pci/pt3/pt3.c
+++ b/drivers/media/pci/pt3/pt3.c
@@ -707,18 +707,10 @@ static int pt3_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret < 0)
 		return ret;
 
-	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
-	if (ret == 0)
-		dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
-	else {
-		ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
-		if (ret == 0)
-			dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
-		else {
-			dev_err(&pdev->dev, "Failed to set DMA mask\n");
-			return ret;
-		}
-		dev_info(&pdev->dev, "Use 32bit DMA\n");
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to set DMA mask\n");
+		return ret;
 	}
 
 	pt3 = devm_kzalloc(&pdev->dev, sizeof(*pt3), GFP_KERNEL);
-- 
2.32.0

Re: [PATCH] media: pt3: Use dma_set_mask_and_coherent() and simplify code

Posted by Akihiro TSUKADA 4 years, 5 months ago

> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/media/pci/pt3/pt3.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/pci/pt3/pt3.c
> b/drivers/media/pci/pt3/pt3.c
> index 0d51bdf01f43..11f26cac0abc 100644
> --- a/drivers/media/pci/pt3/pt3.c
> +++ b/drivers/media/pci/pt3/pt3.c
> @@ -707,18 +707,10 @@ static int pt3_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
>         if (ret < 0)
>                 return ret;
>  
> -       ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
> -       if (ret == 0)
> -               dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
> -       else {
> -               ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
> -               if (ret == 0)
> -                       dma_set_coherent_mask(&pdev->dev,
> DMA_BIT_MASK(32));
> -               else {
> -                       dev_err(&pdev->dev, "Failed to set DMA
> mask\n");
> -                       return ret;
> -               }
> -               dev_info(&pdev->dev, "Use 32bit DMA\n");
> +       ret = dma_set_mask_and_coherent(&pdev->dev,
> DMA_BIT_MASK(64));
> +       if (ret) {
> +               dev_err(&pdev->dev, "Failed to set DMA mask\n");
> +               return ret;
>         }
>  
>         pt3 = devm_kzalloc(&pdev->dev, sizeof(*pt3), GFP_KERNEL);

tested on x86_64.

Acked-by: Akihiro Tsukada <tskd08@gmail.com>