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

Message ID 20230306090919.2206871-2-u.kleine-koenig@pengutronix.de
State New
Headers
Series watchdog: s3c2410_wdt: Simplify using dev_err_probe() |

Commit Message

Uwe Kleine-König March 6, 2023, 9:09 a.m. UTC
  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)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/watchdog/s3c2410_wdt.c | 70 +++++++++++++++-------------------
 1 file changed, 30 insertions(+), 40 deletions(-)
  

Comments

Guenter Roeck March 6, 2023, 5:17 p.m. UTC | #1
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.

Maybe I am old fashioned. Maybe the old "split your code into multiple functions
if the function size is larger than X lines" no longer applies, and it is now
"never split functions unless the separated function is called more than once".
Still, I am quite concerned that accepting this patch would result in a flurry
of similar patches which would all do nothing but hurt readability, using the
same set of arguments. I really don't like where this is going. I am going to
leave it up to Wim to decide if and how to proceed.

Guenter
  
Uwe Kleine-König March 6, 2023, 5:47 p.m. UTC | #2
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:

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
  
Guenter Roeck March 6, 2023, 6:12 p.m. UTC | #3
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
>
  

Patch

diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 58b262ca4e88..7382bf038161 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -579,11 +579,27 @@  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 void s3c2410wdt_wdt_disable_action(void *data)
+{
+	s3c2410wdt_enable(data, false);
+}
+
+static int s3c2410wdt_probe(struct platform_device *pdev)
 {
-	const struct s3c2410_wdt_variant *variant;
 	struct device *dev = &pdev->dev;
+	const struct s3c2410_wdt_variant *variant;
+	struct s3c2410_wdt *wdt;
+	unsigned int wtcon;
+	int wdt_irq;
+	int ret;
+
+	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
+	if (!wdt)
+		return -ENOMEM;
+
+	wdt->dev = dev;
+	spin_lock_init(&wdt->lock);
+	wdt->wdt_device = s3c2410_wdd;
 
 	variant = of_device_get_match_data(dev);
 	if (!variant) {
@@ -597,56 +613,30 @@  s3c2410_get_wdt_drv_data(struct platform_device *pdev)
 	if (variant == &drv_data_exynos850_cl0 ||
 	    variant == &drv_data_exynosautov9_cl0) {
 		u32 index;
-		int err;
 
-		err = of_property_read_u32(dev->of_node,
+		ret = of_property_read_u32(dev->of_node,
 					   "samsung,cluster-index", &index);
-		if (err) {
+		if (ret) {
 			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) ?
-				&drv_data_exynos850_cl1 :
-				&drv_data_exynosautov9_cl1;
+			if (variant == &drv_data_exynos850_cl0)
+				variant = &drv_data_exynos850_cl1;
+			else
+				variant = &drv_data_exynosautov9_cl1;
+			break;
 		default:
 			dev_err(dev, "wrong cluster index: %u\n", index);
-			return NULL;
+			return -EINVAL;
 		}
 	}
 #endif
-
-	return variant;
-}
-
-static void s3c2410wdt_wdt_disable_action(void *data)
-{
-	s3c2410wdt_enable(data, false);
-}
-
-static int s3c2410wdt_probe(struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	struct s3c2410_wdt *wdt;
-	unsigned int wtcon;
-	int wdt_irq;
-	int ret;
-
-	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
-	if (!wdt)
-		return -ENOMEM;
-
-	wdt->dev = dev;
-	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;
+	wdt->drv_data = variant;
 
 	if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
 		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,