On Wed, Aug 12, 2009 at 16:26, Rick L. Vinyard, Jr.<rvinyard@xxxxxxxxxxx> wrote: > I'd like to allow userspace applications to track and display state > changes (without polling) in a driver that exports attributes via sysfs. > > What is the best way to notify userspace applications when a sysfs > exported attribute changes? > > In particular I wanted to drive the notification in the *_store() function > of the sysfs attribute. > > Also, ideally, the mechanism would allow multiple userspace applications > to hook into the notification. There is nothing like this which works out-of-the-box. It needs kernel support for every attribute that should be able to do that. Then poll() can block until the kernel signifies a change, and return with ERR, so the listener wakes up and can read the attribute again. Kay -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
