ChangeSet 1.2054, 2005/03/09 15:39:09-08:00, [EMAIL PROTECTED]
[PATCH] sysdev: remove the rwsem usage from this subsystem.
If further finer grained locking is needed, we can add a lock to the
sysdev_class to
lock the class drivers list. But if you do that, remember the global list also
is still
there and needs to be protected. That's why I went with a simple lock for
everything.
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
drivers/base/sys.c | 21 +++++++++++----------
1 files changed, 11 insertions(+), 10 deletions(-)
diff -Nru a/drivers/base/sys.c b/drivers/base/sys.c
--- a/drivers/base/sys.c 2005-03-09 16:28:10 -08:00
+++ b/drivers/base/sys.c 2005-03-09 16:28:10 -08:00
@@ -103,6 +103,7 @@
static LIST_HEAD(sysdev_drivers);
+static DECLARE_MUTEX(sysdev_drivers_lock);
/**
* sysdev_driver_register - Register auxillary driver
@@ -119,7 +120,7 @@
int sysdev_driver_register(struct sysdev_class * cls,
struct sysdev_driver * drv)
{
- down_write(&system_subsys.rwsem);
+ down(&sysdev_drivers_lock);
if (cls && kset_get(&cls->kset)) {
list_add_tail(&drv->entry, &cls->drivers);
@@ -131,7 +132,7 @@
}
} else
list_add_tail(&drv->entry, &sysdev_drivers);
- up_write(&system_subsys.rwsem);
+ up(&sysdev_drivers_lock);
return 0;
}
@@ -144,7 +145,7 @@
void sysdev_driver_unregister(struct sysdev_class * cls,
struct sysdev_driver * drv)
{
- down_write(&system_subsys.rwsem);
+ down(&sysdev_drivers_lock);
list_del_init(&drv->entry);
if (cls) {
if (drv->remove) {
@@ -154,7 +155,7 @@
}
kset_put(&cls->kset);
}
- up_write(&system_subsys.rwsem);
+ up(&sysdev_drivers_lock);
}
EXPORT_SYMBOL_GPL(sysdev_driver_register);
@@ -193,7 +194,7 @@
if (!error) {
struct sysdev_driver * drv;
- down_write(&system_subsys.rwsem);
+ down(&sysdev_drivers_lock);
/* Generic notification is implicit, because it's that
* code that should have called us.
*/
@@ -209,7 +210,7 @@
if (drv->add)
drv->add(sysdev);
}
- up_write(&system_subsys.rwsem);
+ up(&sysdev_drivers_lock);
}
return error;
}
@@ -218,7 +219,7 @@
{
struct sysdev_driver * drv;
- down_write(&system_subsys.rwsem);
+ down(&sysdev_drivers_lock);
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->remove)
drv->remove(sysdev);
@@ -228,7 +229,7 @@
if (drv->remove)
drv->remove(sysdev);
}
- up_write(&system_subsys.rwsem);
+ up(&sysdev_drivers_lock);
kobject_unregister(&sysdev->kobj);
}
@@ -255,7 +256,7 @@
pr_debug("Shutting Down System Devices\n");
- down_write(&system_subsys.rwsem);
+ down(&sysdev_drivers_lock);
list_for_each_entry_reverse(cls, &system_subsys.kset.list,
kset.kobj.entry) {
struct sys_device * sysdev;
@@ -284,7 +285,7 @@
cls->shutdown(sysdev);
}
}
- up_write(&system_subsys.rwsem);
+ up(&sysdev_drivers_lock);
}
-
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