Re: [PATCH 1/3] watchdog: s3c2410_wdt: Fold s3c2410_get_wdt_drv_data() into only caller

[Guenter Roeck]

On 3/6/23 09:47, Uwe Kleine-König wrote:
> On Mon, Mar 06, 2023 at 09:17:23AM -0800, Guenter Roeck wrote:
> > On 3/6/23 01:09, Uwe Kleine-König wrote:
> > > s3c2410_get_wdt_drv_data() is only called by s3c2410wdt_probe(), so the
> > > implementation of the former can move to the latter.
> > >
> > > scripts/bloat-o-meter reports for this change (on an ARCH=arm
> > > allmodconfig build):
> > >
> > > 	add/remove: 1/1 grow/shrink: 0/2 up/down: 4/-129 (-125)
> >
> > The reason for separating functions in this case wasn't that the separate function
> > would be called several times. It was to improve code readability. If anything,
> > I would argue that it might sense to split the already lengthy probe function
> > further instead of combining it.
>
> Agreed. For dev_err_probe() to work the following would be alternatively
> possible:

That looks ok to me.

Thanks,
Guenter

> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 58b262ca4e88..564919717761 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -579,8 +579,8 @@ static inline unsigned int s3c2410wdt_get_bootstatus(struct s3c2410_wdt *wdt)
>   	return 0;
>   }
>   
> -static inline const struct s3c2410_wdt_variant *
> -s3c2410_get_wdt_drv_data(struct platform_device *pdev)
> +static inline int
> +s3c2410_get_wdt_drv_data(struct platform_device *pdev, struct s3c2410_wdt *wdt)
>   {
>   	const struct s3c2410_wdt_variant *variant;
>   	struct device *dev = &pdev->dev;
> @@ -603,24 +603,26 @@ s3c2410_get_wdt_drv_data(struct platform_device *pdev)
>   					   "samsung,cluster-index", &index);
>   		if (err) {
>   			dev_err(dev, "failed to get cluster index\n");
> -			return NULL;
> +			return -EINVAL;
>   		}
>   
>   		switch (index) {
>   		case 0:
> -			return variant;
> +			break;
>   		case 1:
> -			return (variant == &drv_data_exynos850_cl0) ?
> +			variant = (variant == &drv_data_exynos850_cl0) ?
>   				&drv_data_exynos850_cl1 :
>   				&drv_data_exynosautov9_cl1;
> +			break;
>   		default:
>   			dev_err(dev, "wrong cluster index: %u\n", index);
> -			return NULL;
> +			return -EINVAL;
>   		}
>   	}
>   #endif
> +	wdt->drv_data = variant;
>   
> -	return variant;
> +	return 0;
>   }
>   
>   static void s3c2410wdt_wdt_disable_action(void *data)
> @@ -644,9 +646,9 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>   	spin_lock_init(&wdt->lock);
>   	wdt->wdt_device = s3c2410_wdd;
>   
> -	wdt->drv_data = s3c2410_get_wdt_drv_data(pdev);
> -	if (!wdt->drv_data)
> -		return -EINVAL;
> +	ret = s3c2410_get_wdt_drv_data(pdev, wdt);
> +	if (ret)
> +		return ret;
>   
>   	if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
>   		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
>
> I didn't check if it's the same as for my initial patch #1, but for an
> allmodconfig ARCH=arm build this also has a nice bloatometer output:
>
> 	add/remove: 1/1 grow/shrink: 0/1 up/down: 4/-104 (-100)
>
> This would allow to make use of dev_err_probe() in
> s3c2410_get_wdt_drv_data() and still maintain the split into two
> functions.
>
> Best regards
> Uwe