linux-kernel - Re: [PATCH 5/5] ACPI: Tie ACPI backlight devices to PCI devices if possible

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: <201102062341.19631.rjw@sisk.pl>
Date:	Sun, 6 Feb 2011 23:41:19 +0100
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Matthew Garrett <mjg59@...f.ucam.org>
Cc:	akpm@...ux-foundation.org, intel-gfx@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org, linux-acpi@...r.kernel.org,
	linux-kernel@...r.kernel.org, rpurdie@...ys.net
Subject: Re: [PATCH 5/5] ACPI: Tie ACPI backlight devices to PCI devices if possible

On Sunday, February 06, 2011, Matthew Garrett wrote:
> On Sun, Feb 06, 2011 at 09:35:07PM +0100, Rafael J. Wysocki wrote:
> > > +		acpi_get_parent(device->dev->handle, &acpi_parent);
> > > +
> > > +		pdev = acpi_get_pci_dev(acpi_parent);
> > > +		if (pdev) {
> > > +			parent = &pdev->dev;
> > > +			pci_dev_put(pdev);
> > > +		}
> > 
> > I'm afraid you can't do that or suspend problems will happen.
> 
> Ugh. Ok, how can we fix this?

Not nicely, I'm afraid.

One possible way is to use device_pm_move_after() to rearrange the devices in
the PM core's suspend list, but that will happen in the video device being
suspended before the new parent (and resumed after it) -- of course, the only
option is to move the ACPI video device after the new parent.

Thanks,
Rafael
--
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/