linux-kernel - Re: [RFC][PATCH 0/2] PM / Sleep: Extended control of suspend/hibernate interfaces

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:	Fri, 14 Oct 2011 12:00:59 -0400 (EDT)
From:	Alan Stern <stern@...land.harvard.edu>
To:	NeilBrown <neilb@...e.de>
cc:	"Rafael J. Wysocki" <rjw@...k.pl>,
	Linux PM list <linux-pm@...r.kernel.org>,
	mark gross <markgross@...gnar.org>,
	LKML <linux-kernel@...r.kernel.org>,
	John Stultz <john.stultz@...aro.org>
Subject: Re: [RFC][PATCH 0/2] PM / Sleep: Extended control of suspend/hibernate
 interfaces

On Fri, 14 Oct 2011, NeilBrown wrote:

> Hi Rafael,
> 
>  What do you mean by "too complicated to use in practice"?  What is you
>  measure for complexity?
>  Using suspend in a race-free way is certainly less complex than - for
>  example - configuring bluetooth.
>  And in what way is it "inadequate for other reasons"? What reasons?
> 
> 
>  The only sane way to handle suspend is for any (suitably privileged) process
>  to be able to request that suspend doesn't happen, and then for one process
>  to initiate suspend when no-one is blocking it.

One of the things Rafael didn't mention is that sometimes a kernel 
driver needs to prevent the system from suspending.  This happens when 
recharging over a USB connection.

There's no simple way for such a driver to communicate with a power
daemon.  The driver has to use something like the wakeup mechanism -- 
but currently that mechanism is optional.

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/