> On 11/26/10 03:15, Marcelo Tosatti wrote: > > On Fri, Nov 26, 2010 at 12:38:28AM +0000, Paul Brook wrote: > >>> This patch enables USB UHCI global suspend/resume feature. The OS will > >>> stop the HC once all ports are suspended. If there is activity on the > >>> port(s), an interrupt signalling remote wakeup will be triggered. > >> > >> I'm pretty sure this is wrong. Suspend/resume works based on physical > >> topology, i.e. the resume notification should go to the the port/hub to > >> which the device is connected, not directly to the host controller. > > > > You are correct in that USB HUB emulation does not propagate resume, but > > this does not make this patch incorrect. > > Well, it does. When the notification is port based our software model > should better reflect that, so we have the chance to add resume > propagation to the hub emulation later on. Exactly. The patch assumes the device is connected to a root hub port. This assumption is incorrect. The device should be sending the resume signal to the port/hub to which it is connected. If that hub is still active it will reactivate the port, and flag a port change notification in the normal manner. If the hub is also suspended it will propagate the resume notification upstream (which may or may not be the root hub). Paul -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
