On Fri, Jan 25, 2013 at 05:09:19PM -0500, Alan Stern wrote: > Greg: > > The following series addresses a minor problem caused by a change > introduced in 3.8-rc1. Because the autosuspend delay for hubs is now > set to 0, the PM core will try to runtime-suspend root hubs during an > ongoing port resume (the root hub appears to be idle at such times). > Although the attempted runtime suspend will fail -- the HCD rejects it > because of the resuming port -- the PM core will simply try to do > another suspend, over and over again, until the port is finished > resuming and the root hub appears to be in use. > > We don't want all this futile, unnecessary activity to take place. > The first patch in the series adds a mechanism whereby HCDs can inform > usbcore about port resumes, allowing usbcore to prevent runtime > suspends of the root hub. The second and third patches add the > appropriate calls to ehci-hcd and uhci-hcd. No analogous change is > needed in ohci-hcd because it generates interrupts when port resumes > end rather than when they begin. > > However it's quite possible that xhci-hcd will need a similar change. > I haven't looked at it yet. > > All these patches should be merged by 3.8-final, if timing permits. This serial patchset also fixed my observed problem using usb remote wakeup, no hub suspend has observed during usb system resumes. > > 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 > -- Best Regards, Peter Chen -- 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
