[PATCH] base: soc: Make soc_device_match() simpler and easier to read

[PATCH] base: soc: Make soc_device_match() simpler and easier to read

[Geert Uytterhoeven]

The function soc_device_match() is difficult to read for various
reasons:
  - There are two loop conditions using different styles: "while (...)"
    (which is BTW always true) vs. "if ... break",
  - The are two return condition using different logic: "if ... return
    foo" vs. "if ... else return bar".

Make the code easier to read by:
  1. Removing the always-true "!ret" loop condition, and dropping the
     now unneeded pre-initialization of "ret",
  2. Converting "if ... break" to a proper "while (...)" loop condition,
  3. Inverting the logic of the second return condition.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/base/soc.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/base/soc.c b/drivers/base/soc.c
index 0af5363a582c36dd..22130b5f789d9d7e 100644
--- a/drivers/base/soc.c
+++ b/drivers/base/soc.c
@@ -241,15 +241,13 @@ static int soc_device_match_one(struct device *dev, void *arg)
 const struct soc_device_attribute *soc_device_match(
 	const struct soc_device_attribute *matches)
 {
-	int ret = 0;
+	int ret;
 
 	if (!matches)
 		return NULL;
 
-	while (!ret) {
-		if (!(matches->machine || matches->family ||
-		      matches->revision || matches->soc_id))
-			break;
+	while (matches->machine || matches->family || matches->revision ||
+	       matches->soc_id) {
 		ret = bus_for_each_dev(&soc_bus_type, NULL, (void *)matches,
 				       soc_device_match_one);
 		if (ret < 0 && early_soc_dev_attr)
@@ -257,10 +255,10 @@ const struct soc_device_attribute *soc_device_match(
 						    matches);
 		if (ret < 0)
 			return NULL;
-		if (!ret)
-			matches++;
-		else
+		if (ret)
 			return matches;
+
+		matches++;
 	}
 	return NULL;
 }
-- 
2.25.1

Re: [PATCH] base: soc: Make soc_device_match() simpler and easier to read

[Arnd Bergmann]

On Tue, Mar 1, 2022 at 12:10 PM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
>
> The function soc_device_match() is difficult to read for various
> reasons:
>   - There are two loop conditions using different styles: "while (...)"
>     (which is BTW always true) vs. "if ... break",
>   - The are two return condition using different logic: "if ... return
>     foo" vs. "if ... else return bar".
>
> Make the code easier to read by:
>   1. Removing the always-true "!ret" loop condition, and dropping the
>      now unneeded pre-initialization of "ret",
>   2. Converting "if ... break" to a proper "while (...)" loop condition,
>   3. Inverting the logic of the second return condition.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---

Reviewed-by: Arnd Bergmann <arnd@arndb.de>