[PATCH v2][next] tty: sunsu: Simplify device_node cleanup by using __free

From: Shresth Prasad
Date: Wed May 01 2024 - 04:41:46 EST


Add `__free` function attribute to `ap` and `match` pointer
initialisations which ensure that the pointers are freed as soon as they
go out of scope, thus removing the need to manually free them using
`of_node_put`.

This also removes the need for the `goto` statement and the `rc`
variable.

Tested using a qemu x86_64 virtual machine.

Suggested-by: Julia Lawall <julia.lawall@xxxxxxxx>
Signed-off-by: Shresth Prasad <shresthprasad7@xxxxxxxxx>
---
Changes in v2:
- Specify how the patch was tested

drivers/tty/serial/sunsu.c | 37 +++++++++++--------------------------
1 file changed, 11 insertions(+), 26 deletions(-)

diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 67a5fc70bb4b..0f463da5e7ce 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -1382,44 +1382,29 @@ static inline struct console *SUNSU_CONSOLE(void)

static enum su_type su_get_type(struct device_node *dp)
{
- struct device_node *ap = of_find_node_by_path("/aliases");
- enum su_type rc = SU_PORT_PORT;
+ struct device_node *ap __free(device_node) =
+ of_find_node_by_path("/aliases");

if (ap) {
const char *keyb = of_get_property(ap, "keyboard", NULL);
const char *ms = of_get_property(ap, "mouse", NULL);
- struct device_node *match;

if (keyb) {
- match = of_find_node_by_path(keyb);
+ struct device_node *match __free(device_node) =
+ of_find_node_by_path(keyb);

- /*
- * The pointer is used as an identifier not
- * as a pointer, we can drop the refcount on
- * the of__node immediately after getting it.
- */
- of_node_put(match);
-
- if (dp == match) {
- rc = SU_PORT_KBD;
- goto out;
- }
+ if (dp == match)
+ return SU_PORT_KBD;
}
if (ms) {
- match = of_find_node_by_path(ms);
+ struct device_node *match __free(device_node) =
+ of_find_node_by_path(ms);

- of_node_put(match);
-
- if (dp == match) {
- rc = SU_PORT_MS;
- goto out;
- }
+ if (dp == match)
+ return SU_PORT_MS;
}
}
-
-out:
- of_node_put(ap);
- return rc;
+ return SU_PORT_PORT;
}

static int su_probe(struct platform_device *op)
--
2.44.0