linux-kernel - Re: Attempted summary of suspend-blockers LKML thread, take three

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:	Sat, 14 Aug 2010 11:15:43 -0700 (PDT)
From:	David Brownell <david-b@...bell.net>
To:	paulmck@...ux.vnet.ibm.com, Arjan van de Ven <arjan@...radead.org>
Cc:	Pavel Machek <pavel@....cz>, Alan Cox <alan@...rguk.ukuu.org.uk>,
	Felipe Contreras <felipe.contreras@...il.com>,
	Ted Ts'o <tytso@....edu>, david@...g.hm,
	Brian Swetland <swetland@...gle.com>,
	linux-pm@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
	arve@...roid.com, mjg59@...f.ucam.org, florian@...kler.org,
	rjw@...k.pl, stern@...land.harvard.edu, peterz@...radead.org,
	tglx@...utronix.de, menage@...gle.com, James.Bottomley@...e.de,
	swmike@....pp.se, galibert@...ox.com, dipankar@...ibm.com
Subject: Re: Attempted summary of suspend-blockers LKML thread, take three



--- On Sat, 8/14/10, Arjan van de Ven <arjan@...radead.org> wrote:


> however I think you're making an assumption
> that there is a real difference between a deep idle state and "off"....
> 
> For modern x86 hardware, that assumption isn't
> really valid.

For ARM processors it's not unrealistic.  THey
tend to have idle states that place constraints on
peripherals and clocks which allow peripherals to run independently of CPUs.

I recall for example various processors that allow
USB to continue operating in one or more idle states, if the right clocks are active (and RAM).
Similarly with some other peripherals.  It may be
desirable to have I/O active while CPUs are idle.

Not all low power states map to x86/ACPI models;
and Linux hasn't accomodated that reality well.



--
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/