From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oliver Neukum <oliver@neukum.org>
Subject: Re: [RFC][PATCH] PM: Introduce new top level suspend and hibernation callbacks (rev. 6)
Date: Wed, 2 Apr 2008 16:22:03 +0200
Message-ID: <200804021622.04461.oliver@neukum.org>
References: <Pine.LNX.4.44L0.0804021007060.14858-100000@iolanthe.rowland.org>
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To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, Nigel Cunningham <ncunningham@crca.org.au>, pm list <linux-pm@lists.linux-foundation.org>, ACPI Devel Maling List <linux-acpi@vger.kernel.org>, Greg KH <greg@kroah.com>, Len Brown <lenb@kernel.org>, LKML <linux-kernel@vger.kernel.org>, Alexey Starikovskiy <astarikovskiy@suse.de>, David Brownell <david-b@pacbell.net>, Pavel Machek <pavel@ucw.cz>, Benjamin Herrenschmidt <benh@kernel.crashing.org>

Am Mittwoch, 2. April 2008 16:11:14 schrieb Alan Stern:
> > However, I'd like to add a recommendation that the _new_ "resume" c=
allbacks
> > should only return errors in critical situations as the indication =
to the PM
> > core that something went _really_ wrong and the device in question =
is quite
> > surely unusable.
>=20
> Agreed. =A0The most important aspect is that drivers should _not_ ret=
urn
> an error if the device is working correctly. =A0We should fix the dri=
vers=20
> which make this mistake.

We need to do something about devices that don't want to be resumed.
There's code like this:


static int usb_resume(struct device *dev)
{
	struct usb_device	*udev;

	if (!is_usb_device(dev))	/* Ignore PM for interfaces */
		return 0;
	udev =3D to_usb_device(dev);

	/* If udev->skip_sys_resume is set then udev was already suspended
	 * when the system suspend started, so we don't want to resume
	 * udev during this system wakeup.  However a reset-resume counts
	 * as a wakeup event, so allow a reset-resume to occur if remote
	 * wakeup is enabled. */
	if (udev->skip_sys_resume) {
		if (!(udev->reset_resume && udev->do_remote_wakeup))
			return -EHOSTUNREACH;
	}
	return usb_external_resume_device(udev);
}

Do we want to keep this in the subsystems?

	Regards
		Oliver
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