A better way to sequence driver initialization?
Bill Gatliff
bgat at billgatliff.com
Sat Apr 10 14:19:52 EST 2010
Bill Gatliff wrote:
>
> ... and kset_register() might be the only place that calls
> wake_up_interruptible(). Wow.
>
Wow, indeed. With just the attached patch, I get exactly one OOPS
now--- in ssc_free(), which I think is getting called because
atmel_ssc_modinit() is racing with something.
I wasn't able to get all the way to mounting my NFS rootfs, I think
because I'm getting to ip_auto_config() before my ethernet controller
has registered! :)
$ git diff lib/kobject.c
diff --git a/lib/kobject.c b/lib/kobject.c
index b512b74..e75556c 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -18,6 +18,10 @@
#include <linux/stat.h>
#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+DECLARE_WAIT_QUEUE_HEAD(kset_wait);
+
/*
* populate_dir - populate directory with attributes.
* @kobj: object we're working on.
@@ -721,6 +725,7 @@ int kset_register(struct kset *k)
if (err)
return err;
kobject_uevent(&k->kobj, KOBJ_ADD);
+ wake_up_interruptible(&kset_wait);
return 0;
}
@@ -744,7 +749,7 @@ void kset_unregister(struct kset *k)
* looking for a matching kobject. If matching object is found
* take a reference and return the object.
*/
-struct kobject *kset_find_obj(struct kset *kset, const char *name)
+struct kobject *__kset_find_obj(struct kset *kset, const char *name)
{
struct kobject *k;
struct kobject *ret = NULL;
@@ -760,6 +765,14 @@ struct kobject *kset_find_obj(struct kset *kset,
const char *name)
return ret;
}
+struct kobject *kset_find_obj(struct kset *kset, const char *name)
+{
+ struct kobject *ret = NULL;
+ wait_event_interruptible(kset_wait, (ret = __kset_find_obj(kset,
name)));
+ return ret;
+}
+
static void kset_release(struct kobject *kobj)
{
struct kset *kset = container_of(kobj, struct kset, kobj);
b.g.
--
Bill Gatliff
bgat at billgatliff.com
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