drm: mediatek: Drop unnecessary check for property presence

[PATCH] drm: mediatek: Drop unnecessary check for property presence

Posted by Rob Herring (Arm) 1 year, 6 months ago

of_property_read_u32() returns -EINVAL if a property is not present, so
the preceeding check for presence with of_find_property() can be
dropped. Really, what the errno is shouldn't matter. Either the property
can be read and used or it can't and is ignored.

This is part of a larger effort to remove callers of of_find_property()
and similar functions. of_find_property() leaks the DT struct property
and data pointers which is a problem for dynamically allocated nodes
which may be freed.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
---
 drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
index 634bbba5d43f..07243f372260 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -341,14 +341,11 @@ static int mtk_disp_rdma_probe(struct platform_device *pdev)
 		dev_dbg(dev, "get mediatek,gce-client-reg fail!\n");
 #endif
 
-	if (of_find_property(dev->of_node, "mediatek,rdma-fifo-size", &ret)) {
-		ret = of_property_read_u32(dev->of_node,
-					   "mediatek,rdma-fifo-size",
-					   &priv->fifo_size);
-		if (ret)
-			return dev_err_probe(dev, ret,
-					     "Failed to get rdma fifo size\n");
-	}
+	ret = of_property_read_u32(dev->of_node,
+				   "mediatek,rdma-fifo-size",
+				   &priv->fifo_size);
+	if (ret && (ret != -EINVAL))
+		return dev_err_probe(dev, ret, "Failed to get rdma fifo size\n");
 
 	/* Disable and clear pending interrupts */
 	writel(0x0, priv->regs + DISP_REG_RDMA_INT_ENABLE);
-- 
2.43.0

Re: [PATCH] drm: mediatek: Drop unnecessary check for property presence

Posted by Chun-Kuang Hu 1 year, 5 months ago

Hi, Rob:

Rob Herring (Arm) <robh@kernel.org> 於 2024年8月1日 週四 上午4:14寫道：
>
> of_property_read_u32() returns -EINVAL if a property is not present, so
> the preceeding check for presence with of_find_property() can be
> dropped. Really, what the errno is shouldn't matter. Either the property
> can be read and used or it can't and is ignored.
>
> This is part of a larger effort to remove callers of of_find_property()
> and similar functions. of_find_property() leaks the DT struct property
> and data pointers which is a problem for dynamically allocated nodes
> which may be freed.

Applied to mediatek-drm-next [1], thanks.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next

Regards,
Chun-Kuang.

>
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> index 634bbba5d43f..07243f372260 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> @@ -341,14 +341,11 @@ static int mtk_disp_rdma_probe(struct platform_device *pdev)
>                 dev_dbg(dev, "get mediatek,gce-client-reg fail!\n");
>  #endif
>
> -       if (of_find_property(dev->of_node, "mediatek,rdma-fifo-size", &ret)) {
> -               ret = of_property_read_u32(dev->of_node,
> -                                          "mediatek,rdma-fifo-size",
> -                                          &priv->fifo_size);
> -               if (ret)
> -                       return dev_err_probe(dev, ret,
> -                                            "Failed to get rdma fifo size\n");
> -       }
> +       ret = of_property_read_u32(dev->of_node,
> +                                  "mediatek,rdma-fifo-size",
> +                                  &priv->fifo_size);
> +       if (ret && (ret != -EINVAL))
> +               return dev_err_probe(dev, ret, "Failed to get rdma fifo size\n");
>
>         /* Disable and clear pending interrupts */
>         writel(0x0, priv->regs + DISP_REG_RDMA_INT_ENABLE);
> --
> 2.43.0
>

Re: [PATCH] drm: mediatek: Drop unnecessary check for property presence

Posted by CK Hu (胡俊光) 1 year, 5 months ago

Hi, Rob:

On Wed, 2024-07-31 at 14:13 -0600, Rob Herring (Arm) wrote:
>  	 
> External email : Please do not click links or open attachments until you have verified the sender or the content.
>  of_property_read_u32() returns -EINVAL if a property is not present, so
> the preceeding check for presence with of_find_property() can be
> dropped. Really, what the errno is shouldn't matter. Either the property
> can be read and used or it can't and is ignored.
> 
> This is part of a larger effort to remove callers of of_find_property()
> and similar functions. of_find_property() leaks the DT struct property
> and data pointers which is a problem for dynamically allocated nodes
> which may be freed.

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> index 634bbba5d43f..07243f372260 100644
> --- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> +++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
> @@ -341,14 +341,11 @@ static int mtk_disp_rdma_probe(struct platform_device *pdev)
>  		dev_dbg(dev, "get mediatek,gce-client-reg fail!\n");
>  #endif
>  
> -	if (of_find_property(dev->of_node, "mediatek,rdma-fifo-size", &ret)) {
> -		ret = of_property_read_u32(dev->of_node,
> -					   "mediatek,rdma-fifo-size",
> -					   &priv->fifo_size);
> -		if (ret)
> -			return dev_err_probe(dev, ret,
> -					     "Failed to get rdma fifo size\n");
> -	}
> +	ret = of_property_read_u32(dev->of_node,
> +				   "mediatek,rdma-fifo-size",
> +				   &priv->fifo_size);
> +	if (ret && (ret != -EINVAL))
> +		return dev_err_probe(dev, ret, "Failed to get rdma fifo size\n");
>  
>  	/* Disable and clear pending interrupts */
>  	writel(0x0, priv->regs + DISP_REG_RDMA_INT_ENABLE);
> -- 
> 2.43.0

Re: [PATCH] drm: mediatek: Drop unnecessary check for property presence

Posted by AngeloGioacchino Del Regno 1 year, 6 months ago

Il 31/07/24 22:13, Rob Herring (Arm) ha scritto:
> of_property_read_u32() returns -EINVAL if a property is not present, so
> the preceeding check for presence with of_find_property() can be
> dropped. Really, what the errno is shouldn't matter. Either the property
> can be read and used or it can't and is ignored.
> 
> This is part of a larger effort to remove callers of of_find_property()
> and similar functions. of_find_property() leaks the DT struct property
> and data pointers which is a problem for dynamically allocated nodes
> which may be freed.
> 
> Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>