linux-kernel - Re: [PATCH 6/6] USB / PM: Allow USB devices to remain runtime-suspended when sleeping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.44L0.1504011035540.1420-100000@iolanthe.rowland.org>
Date:	Wed, 1 Apr 2015 10:36:50 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	Oliver Neukum <oneukum@...e.de>
cc:	Tomeu Vizoso <tomeu.vizoso@...labora.com>,
	Linux-pm mailing list <linux-pm@...r.kernel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Scot Doyle <lkml14@...tdoyle.com>,
	Dan Williams <dan.j.williams@...el.com>,
	Julius Werner <jwerner@...omium.org>,
	"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	USB list <linux-usb@...r.kernel.org>,
	Kernel development list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 6/6] USB / PM: Allow USB devices to remain runtime-suspended
 when sleeping

On Wed, 1 Apr 2015, Oliver Neukum wrote:

> On Wed, 2015-04-01 at 10:01 -0400, Alan Stern wrote:
> > On Wed, 1 Apr 2015, Oliver Neukum wrote:
> > 
> > > On Tue, 2015-03-31 at 13:09 -0400, Alan Stern wrote:
> > > > In other words, if the device is currently in runtime suspend with 
> > > > remote wakeup enabled, but device_may_wakeup() returns 0 (so that the 
> > > > device should be disabled for wakeup when the system goes into 
> > > > suspend), then the prepare callback has to return 0.
> > > > 
> > > > Therefore what you need to do here is something like this:
> > > > 
> > > >         struct usb_device       *udev = to_usb_device(dev);
> > > > 
> > > >         /* Return 0 if the current wakeup setting is wrong, otherwise
> > > > 1 */
> > > 
> > > And the other way round?
> > 
> > Your meaning isn't clear.  Are you asking what should happen if the 
> > device is in runtime suspend with remote wakeup disabled, but 
> > device_may_wakeup() returns 1?
> 
> Yes. I was thinking about that case.
> 
> >   That case should never happen -- but 
> > if it does then the prepare callback should return 0.
> 
> Exactly. It didn't seem to do so.

Well, Tomeu can fix it up to handle both cases properly.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/