[PATCH] add sysfs attr to re-emit device hotplug event

A "coldplug + udevstart" can be simple like this:
  for i in /sys/block/*/*/uevent; do echo 1 > $i; done
  for i in /sys/class/*/*/uevent; do echo 1 > $i; done
  for i in /sys/bus/*/devices/*/uevent; do echo 1 > $i; done

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 31109193e2c4..ac4b5fdd95f5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -154,6 +154,13 @@ static struct kset_hotplug_ops device_hotplug_ops = {
         .hotplug =      dev_hotplug,
 };
 
+static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
+                            const char *buf, size_t count)
+{
+        kobject_hotplug(&dev->kobj, KOBJ_ADD);
+        return count;
+}
+
 /**
  *      device_subsys - structure to be registered with kobject core.
  */
@@ -259,6 +266,14 @@ int device_add(struct device *dev)
 
         if ((error = kobject_add(&dev->kobj)))
                 goto Error;
+
+        dev->uevent_attr.attr.name = "uevent";
+        dev->uevent_attr.attr.mode = S_IWUSR;
+        if (dev->driver)
+                dev->uevent_attr.attr.owner = dev->driver->owner;
+        dev->uevent_attr.store = store_uevent;
+        device_create_file(dev, &dev->uevent_attr);
+
         kobject_hotplug(&dev->kobj, KOBJ_ADD);
         if ((error = device_pm_add(dev)))
                 goto PMError;
@@ -350,6 +365,7 @@ void device_del(struct device * dev)
 
         if (parent)
                 klist_del(&dev->knode_parent);
+        device_remove_file(dev, &dev->uevent_attr);
 
         /* Notify the platform of the removal, in case they
          * need to do anything...