[PATCH v2] soc: mediatek: Simplify with dev_err_probe()

[PATCH v2] soc: mediatek: Simplify with dev_err_probe()

[Yan Zhen]

Using dev_err_probe() to simplify the error path and unify a 
message template.

Using this helper is totally fine even if err is known to never
be -EPROBE_DEFER.

The benefit compared to a normal dev_err() is the standardized format
of the error code, it being emitted symbolically and the fact that
the error code is returned which allows more compact error paths.

Signed-off-by: Yan Zhen <yanzhen@vivo.com>
---

Changes in v2:
- Get rid of `ret = PTR_ERR(mmsys->regs);`.

 drivers/soc/mediatek/mtk-mmsys.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
index 938240714e54..a6e0c41c10ab 100644
--- a/drivers/soc/mediatek/mtk-mmsys.c
+++ b/drivers/soc/mediatek/mtk-mmsys.c
@@ -397,11 +397,9 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	mmsys->regs = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(mmsys->regs)) {
-		ret = PTR_ERR(mmsys->regs);
-		dev_err(dev, "Failed to ioremap mmsys registers: %d\n", ret);
-		return ret;
-	}
+	if (IS_ERR(mmsys->regs))
+		return dev_err_probe(dev, PTR_ERR(mmsys->regs),
+					"Failed to ioremap mmsys registers");
 
 	mmsys->data = of_device_get_match_data(&pdev->dev);
 
@@ -413,10 +411,9 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
 		mmsys->rcdev.ops = &mtk_mmsys_reset_ops;
 		mmsys->rcdev.of_node = pdev->dev.of_node;
 		ret = devm_reset_controller_register(&pdev->dev, &mmsys->rcdev);
-		if (ret) {
-			dev_err(&pdev->dev, "Couldn't register mmsys reset controller: %d\n", ret);
-			return ret;
-		}
+		if (ret)
+			dev_err_probe(&pdev->dev, ret,
+					"Couldn't register mmsys reset controller");
 	}
 
 	/* CMDQ is optional */
-- 
2.34.1

Re: [PATCH v2] soc: mediatek: Simplify with dev_err_probe()

[Nícolas F. R. A. Prado]

Hi,

thank you for the patch. See comments below.

On Fri, Aug 30, 2024 at 04:05:38PM +0800, Yan Zhen wrote:
> Using dev_err_probe() to simplify the error path and unify a 
> message template.
> 

From [1]:

  Describe your changes in imperative mood, e.g. “make xyzzy do frotz” instead of
  “[This patch] makes xyzzy do frotz” or “[I] changed xyzzy to do frotz”, as if
  you are giving orders to the codebase to change its behaviour.

[1] https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

So should be "Use dev_err_probe()...".

Also, the commit summary seems a bit too broad, please add "mtk-mmsys:" in the
subsystem:

  soc: mediatek: mtk-mmsys: Simplify with dev_err_probe()

> Using this helper is totally fine even if err is known to never
> be -EPROBE_DEFER.
> 
> The benefit compared to a normal dev_err() is the standardized format
> of the error code, it being emitted symbolically and the fact that
> the error code is returned which allows more compact error paths.
> 
> Signed-off-by: Yan Zhen <yanzhen@vivo.com>
> ---
> 
> Changes in v2:
> - Get rid of `ret = PTR_ERR(mmsys->regs);`.
> 
>  drivers/soc/mediatek/mtk-mmsys.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/soc/mediatek/mtk-mmsys.c b/drivers/soc/mediatek/mtk-mmsys.c
> index 938240714e54..a6e0c41c10ab 100644
> --- a/drivers/soc/mediatek/mtk-mmsys.c
> +++ b/drivers/soc/mediatek/mtk-mmsys.c
> @@ -397,11 +397,9 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	mmsys->regs = devm_platform_ioremap_resource(pdev, 0);
> -	if (IS_ERR(mmsys->regs)) {
> -		ret = PTR_ERR(mmsys->regs);
> -		dev_err(dev, "Failed to ioremap mmsys registers: %d\n", ret);
> -		return ret;
> -	}
> +	if (IS_ERR(mmsys->regs))
> +		return dev_err_probe(dev, PTR_ERR(mmsys->regs),
> +					"Failed to ioremap mmsys registers");

You're missing the \n at the end of the string.

Also, would look nicer if it was aligned like so:

		return dev_err_probe(dev, PTR_ERR(mmsys->regs),
				     "Failed to ioremap mmsys registers\n");

>  
>  	mmsys->data = of_device_get_match_data(&pdev->dev);
>  
> @@ -413,10 +411,9 @@ static int mtk_mmsys_probe(struct platform_device *pdev)
>  		mmsys->rcdev.ops = &mtk_mmsys_reset_ops;
>  		mmsys->rcdev.of_node = pdev->dev.of_node;
>  		ret = devm_reset_controller_register(&pdev->dev, &mmsys->rcdev);
> -		if (ret) {
> -			dev_err(&pdev->dev, "Couldn't register mmsys reset controller: %d\n", ret);
> -			return ret;
> -		}
> +		if (ret)
> +			dev_err_probe(&pdev->dev, ret,
> +					"Couldn't register mmsys reset controller");

You're missing the return here. And the \n is also missing.

Also, here checkpatch actually complains about the alignment (run
'scripts/checkpatch.pl --strict' on your patch).

CHECK: Alignment should match open parenthesis
#50: FILE: drivers/soc/mediatek/mtk-mmsys.c:416:
+			dev_err_probe(&pdev->dev, ret,
+					"Couldn't register mmsys reset controller");

After making those changes you can add

Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>

Thanks,
Nícolas