On Sun, 29 Dec 2019, Guenter Roeck wrote: > On Sat, Dec 28, 2019 at 02:33:01PM -0500, Alan Stern wrote: > > > > Let's try a slightly different approach. What happens with this patch? > > > > Alan Stern > > > > > > Index: usb-devel/drivers/usb/core/hub.c > > =================================================================== > > --- usb-devel.orig/drivers/usb/core/hub.c > > +++ usb-devel/drivers/usb/core/hub.c > > @@ -1065,6 +1065,7 @@ static void hub_activate(struct usb_hub > > if (type == HUB_INIT) { > > delay = hub_power_on_good_delay(hub); > > > > + hub->power_bits[0] = ~0UL; /* All ports on */ > > hub_power_on(hub, false); > > INIT_DELAYED_WORK(&hub->init_work, hub_init_func2); > > queue_delayed_work(system_power_efficient_wq, > > > > That doesn't make a difference - the traceback is still seen with this patch > applied. Can you trace what's going on? Does this code pathway now end up calling ehci_port_power() for each root-hub port, and from there down into the chipidea driver? If not, can you find where it gets sidetracked? Alan Stern