Alan Stern wrote: > On Mon, 7 Jun 2010, Gadiyar, Anand wrote: > > Hi all, > > > > On the OMAP3, we have a new hardware bug that causes the > > EHCI controller to lock up under heavy stress. The only > > known way to recover is to soft-reset the controller. > > > > I'm trying to implement some kind of recovery mechanism > > for the ehci-omap driver. Is there a way to inform the > > USB core that the root-hub and down-stream devices have > > been reset and need to be re-enumerated? > > There's usb_hc_died(). It tells the core that the controller has > stopped working. The core then removes all devices below the root hub > and marks the root hub as non-operational (the state is set to > USB_STATE_NOTATTACHED). But there is no re-enumeration; from that > point on the root hub is unusable. > > This may not be exactly what you want. Perhaps a better match would be > usb_reset_device(), but that routine specifically excludes root hubs. > You might be able to adjust it in some way, though. > > Another alternative is simply to unregister the hcd and then > re-register it. > (Sorry, hit send before completing the mail) Thanks! As a quick test, I built the driver as a module. And in the remove path, we soft-reset the controller anyway. After a rmmod-insmod sequence I am able to detect new devices, but only if I unplug and plug them in again. Some more debugging to be done - thanks for the pointer. - Anand -- 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
