Re: [PATCH] reset: Further simplify locking with guard()

From: Markus Elfring
Date: Sun Sep 29 2024 - 06:45:55 EST


> Use guard(mutex) to automatically unlock mutexes when going out of
> scope. Simplify error paths by removing a goto and manual mutex
> unlocking in multiple places.

> +++ b/drivers/reset/core.c

@@ -1041,29 +1036,27 @@ __of_reset_control_get(struct device_node *node, const char *id, int index,
}
}

- mutex_lock(&reset_list_mutex);
+ guard(mutex)(&reset_list_mutex);
rcdev = __reset_find_rcdev(&args, gpio_fallback);

rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);

-out_unlock:
- mutex_unlock(&reset_list_mutex);
out_put:
of_node_put(args.np);


Would you like to preserve the same lock scope (which ended before this function call)?


@@ -1098,7 +1091,7 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
const char *dev_id = dev_name(dev);
struct reset_control *rstc = NULL;

- mutex_lock(&reset_lookup_mutex);
+ guard(mutex)(&reset_lookup_mutex);

list_for_each_entry(lookup, &reset_lookup_list, list) {

break;
}
}

- mutex_unlock(&reset_lookup_mutex);
-
if (!rstc)
return optional ? NULL : ERR_PTR(-ENOENT);


Would you really like to increase the lock scope here?

Regards,
Markus