Re: [RFC] usb: Add support for runtime power management of the hcd
From: Oliver Neukum <oliver@neukum.org>
Date: 2009-08-13 12:16:41
Am Donnerstag, 13. August 2009 02:35:44 schrieb Matthew Garrett:
The power savings from this are measurable but not huge - it still seems
How large?
like a decent optimisation. The main problem is that BIOS bugs on some Dell laptops will kill USB if this is used, so we either default to off or add some quirks to handle that case (I have some ideas in that respect).
Your earlier failures don't look promising regarding BIOSes. What do you have in mind?
quoted hunk
@@ -1968,6 +1972,9 @@ struct usb_hcd *usb_create_hcd (const structhc_driver *driver, INIT_WORK(&hcd->wakeup_work, hcd_resume_work); #endif + pm_runtime_enable(dev);
So you don't get a reference from that?
+ pm_runtime_get(dev);
What happens if you get a runtime suspend request in between? Is this a flaw of the API? Regards Oliver