> > Hi Alan, > > In order to support remote wakeup well, we need to take some timing > issues > into consideration. For example, after resuming signal, the SOF must be > sent by host within 3ms, or the device will suspend again, in that case, > the device may be taken as disconnection once host sends SOF. > > For some controllers, the SOF is controlled by usbcmd.rs, only > usbcmd.rs=1, > the host sends SOF. But according to ehci spec, the usbcmd.rs need to be > clear > after bus suspend. The host set usbcmd.rs again at bus resume, but bus > resume > routine may not be called with 20ms (Some controller will end resume > signal > automatically within a little more than 20ms), then the above problem > occurs. > > The usb_hcd_resume_root_hub is only called at PCD interrupt when > usbcmd.rs=0, > I would like to set usbcmd.rs as early as possible (at platform or > controller > code), but don't want break usb core. Current, my solution is run > usb_hcd_resume_root_hub at controller code, and the PCD interrupt will be > triggered later. Any risks for this solution, do you have any better > suggestions? > Is it possible to use other conditions, like hcd->state == HC_STATE_SUSPENDED to run usb_hcd_resume_root_hub at PCD interrupt? > Best regards, > Peter Chen > > MAD Linux BSP Team > Freescale Semiconductor Ltd. > > > > -- > 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 -- 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
