From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Date: Tue, 1 Jun 2010 00:17:13 +0200 (CEST) Message-ID: References: <20100527222514.0a1710bf@lxorguk.ukuu.org.uk> <20100527230806.4deb6de3@lxorguk.ukuu.org.uk> <20100527220949.GB10602@srcf.ucam.org> <20100527232357.6d14fdb2@lxorguk.ukuu.org.uk> <20100527223605.GB11364@srcf.ucam.org> <20100527235546.09f3ce8a@lxorguk.ukuu.org.uk> <20100528043114.GC26177@thunk.org> <1275030704.32462.11.camel@laptop> <1275120618.27810.12699.camel@twins> <1275149418.4503.128.camel@mulgrave.site> <1275340869.2823.344.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <1275340869.2823.344.camel@mulgrave.site> Sender: linux-kernel-owner@vger.kernel.org To: James Bottomley Cc: Peter Zijlstra , =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , tytso@mit.edu, LKML , Florian Mickler , Linux PM , Linux OMAP Mailing List , felipe.balbi@nokia.com, Alan Cox List-Id: linux-omap@vger.kernel.org On Mon, 31 May 2010, James Bottomley wrote: > On Mon, 2010-05-31 at 22:49 +0200, Thomas Gleixner wrote: > > On Sat, 29 May 2010, James Bottomley wrote: > > > The job of the kernel is to accommodate hardware as best it can ... > > > sometimes it might not be able to, but most of the time it does a pretty > > > good job. > > > > > > The facts are that C states and S states are different and are entered > > > differently. > > > > That's an x86'ism which is going away. And that's really completely > > irrelevant for the mobile device space. Can we please stop trying to > > fix todays x86 based laptop problems? They are simply not fixable. > > You're the one mentioning x86, not me. I already explained that some > MSM hardware (the G1 for example) has lower power consumption in S3 > (which I'm using as an ACPI shorthand for suspend to ram) than any > suspend from idle C state. Those machines can go from idle into S2RAM just fine w/o touching the /sys/power/state S2RAM mechanism. It's just a deeper "C" state, really. The confusion is that S3 is considered to be a complete different mechanism - which is true for PC style x86 - but not relevant for hardware which is sane from the PM point of view. Now some people think, that suspend blockers are a cure for the existing x86/ACPI/BIOS mess, which cannot go to S3 from idle, but that's simply not feasible. Thanks, tglx