linux-kernel - Re: pci_set_power_state() failure and breaking suspend

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]

Date:	Tue, 24 Oct 2006 11:09:16 -0500
From:	Scott Wood <scottwood@...escale.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
CC:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	linuxppc-dev list <linuxppc-dev@...abs.org>,
	linux1394-devel@...ts.sourceforge.net,
	Linux Kernel list <linux-kernel@...r.kernel.org>,
	Pavel Machek <pavel@....cz>, Greg KH <greg@...ah.com>
Subject: Re: pci_set_power_state() failure and breaking suspend

Rafael J. Wysocki wrote:
> On Tuesday, 24 October 2006 08:54, Benjamin Herrenschmidt wrote:
>>However, this raises the question of do we actually want to prevent
>>machines to suspend when they have a PCI device that don't have the PCI
>>PM capability ? I'm asking that because I can easily imagine that sort
>>of construct growing into more drivers (sounds logical if you don't
>>think) and I can even imagine somebody thinking it's a good idea to slap
>>a __must_check on pci_set_power_state() ... 
> 
> 
> As far as the suspend to RAM is concerned, I don't know.
> 
> For the suspend to disk we can ignore the error if we know that the device
> in question won't do anything like a DMA transfer into memory while we're
> creating the suspend image.

I think it should be ignored for suspend-to-RAM as well; even if a 
device or two is consuming unnecessary power, it's better than not being 
able to suspend at all, causing more things to consume unnecessary power.

At most, a warning should be issued so the user knows what's going on, 
and can choose whether to suspend to disk instead (or choose to complain 
to the device manufacturer).

-Scott
-
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/