[PATCH] Driver core: add generic "subsystem" link to all devices
Like the SUBSYTEM= key we find in the environment of the uevent, this
creates a generic "subsystem" link in sysfs for every device. Userspace
usually doesn't care at all if its a "class" or a "bus" device. This
provides an unified way to determine the subsytem of a device, regardless
of the way the driver core has created it.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 64ba901..050d86d 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -374,6 +374,7 @@
error = device_add_attrs(bus, dev);
if (!error) {
sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
+ sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "subsystem");
sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
}
}
@@ -408,6 +409,7 @@
void bus_remove_device(struct device * dev)
{
if (dev->bus) {
+ sysfs_remove_link(&dev->kobj, "subsystem");
sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 50e841a..9aa1274 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -561,6 +561,7 @@
goto out2;
/* add the needed attributes to this device */
+ sysfs_create_link(&class_dev->kobj, &parent_class->subsys.kset.kobj, "subsystem");
class_dev->uevent_attr.attr.name = "uevent";
class_dev->uevent_attr.attr.mode = S_IWUSR;
class_dev->uevent_attr.attr.owner = parent_class->owner;
@@ -737,6 +738,7 @@
sysfs_remove_link(&class_dev->kobj, "device");
sysfs_remove_link(&class_dev->dev->kobj, class_name);
}
+ sysfs_remove_link(&class_dev->kobj, "subsystem");
class_device_remove_file(class_dev, &class_dev->uevent_attr);
if (class_dev->devt_attr)
class_device_remove_file(class_dev, class_dev->devt_attr);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 252cf40..cc8bb97 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -319,9 +319,12 @@
dev->devt_attr = attr;
}
- if (dev->class)
+ if (dev->class) {
+ sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
+ "subsystem");
sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
dev->bus_id);
+ }
if ((error = device_pm_add(dev)))
goto PMError;
@@ -422,8 +425,10 @@
klist_del(&dev->knode_parent);
if (dev->devt_attr)
device_remove_file(dev, dev->devt_attr);
- if (dev->class)
+ if (dev->class) {
+ sysfs_remove_link(&dev->kobj, "subsystem");
sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
+ }
device_remove_file(dev, &dev->uevent_attr);
/* Notify the platform of the removal, in case they