Re: [PATCH] usb: chipidea: host: Disable port power only if previously enabled

[Alan Stern]

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