On Wed, 17 Jul 2013, Thomas Pugliese wrote: > Hi, > What is the expected behavior if a host controller does not implement > bus_suspend and bus_resume? I am seeing that with the HWA HCD, kworker > and khubd peg the CPU at 100% because the kernel is constantly calling > hcd_bus_suspend and hcd_bus_resume. The calls to hcd_bus_suspend and > hcd_bus_resume fail because hcd->bus_suspend and hcd->bus_resume are NULL. > I have reproduced this behaviour using 3.11rc1 all the way back to 3.9.2. I think the expected behavior is close to what you described. :-) Seriously, AFAIK nobody thought about this case. To prevent this problem, the HCD's start routine would have to disable runtime PM for the root hub, by calling pm_runtime_disable(&hcd->self.root_hub.dev); Alan Stern -- 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
