Strony Zhang <> wrote: > The reason is that ehci_handle_root_hub_status_change() in ehci driver is > called once every 256 ms to poll the ehci root hub or port status change. > The fix way is to change the polling to the interrupter-driven. Fortunately, > there is a corresponding interrupt enable bit(Port Change Interrupt Enable) > offered in the ehci interrupt register. It will be supported to fix the > issue. > > Regards, > Strony >
This might be one of the causes. 256ms is long enough to let CPUs enter deep package C-state. I guess there must be some other activities from USB. If you can build a driver or make a patch, I'd like to have a try. BTW, is there a CR number of this issue? Or do you need me to file one? Thanks, -Aubrey _______________________________________________ driver-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/driver-discuss
