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From: Guenter Roeck <linux@roeck-us.net>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	USB list <linux-usb@vger.kernel.org>,
	Kernel development list <linux-kernel@vger.kernel.org>,
	Michael Grzeschik <m.grzeschik@pengutronix.de>,
	stable@vger.kernel.org
Subject: Re: [PATCH] usb: chipidea: host: Disable port power only if previously enabled
Date: Sun, 29 Dec 2019 16:57:42 -0800	[thread overview]
Message-ID: <20191230005742.GA25100@roeck-us.net> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1912291137150.19645-100000@netrider.rowland.org>

On Sun, Dec 29, 2019 at 11:40:52AM -0500, Alan Stern wrote:
> 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?
> 
Sure, I'll do that. It will have to wait for the new year, though -
internet connectivity is terrible where I am right now,

Guenter

  reply	other threads:[~2019-12-30  0:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-26 15:57 [PATCH] usb: chipidea: host: Disable port power only if previously enabled Guenter Roeck
2019-12-26 19:46 ` Alan Stern
2019-12-27  1:45   ` Peter Chen
2019-12-27 14:47     ` Alan Stern
2019-12-27 16:55   ` Guenter Roeck
2019-12-28 19:33     ` Alan Stern
2019-12-29 16:28       ` Guenter Roeck
2019-12-29 16:40         ` Alan Stern
2019-12-30  0:57           ` Guenter Roeck [this message]
2020-01-01 22:09           ` Guenter Roeck
2020-01-02  2:30             ` Alan Stern
2019-12-27  1:45 ` Peter Chen

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