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: Thu, 27 May 2010 20:18:49 +0200 (CEST) Message-ID: References: <20100527003943.07c17f85@lxorguk.ukuu.org.uk> <20100527140655.GA28048@srcf.ucam.org> <20100527155201.GA31937@srcf.ucam.org> <20100527165931.GB1062@srcf.ucam.org> <20100527172343.GB2468@srcf.ucam.org> <20100527184918.3d090921@lxorguk.ukuu.org.uk> <20100527175030.GA3543@srcf.ucam.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: In-Reply-To: <20100527175030.GA3543@srcf.ucam.org> Sender: linux-kernel-owner@vger.kernel.org To: Matthew Garrett Cc: Alan Cox , =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= , Florian Mickler , Vitaly Wool , Peter Zijlstra , LKML , Paul@smtp1.linux-foundation.org, felipe.balbi@nokia.com, Linux OMAP Mailing List , Linux PM List-Id: linux-omap@vger.kernel.org On Thu, 27 May 2010, Matthew Garrett wrote: > On Thu, May 27, 2010 at 06:49:18PM +0100, Alan Cox wrote: > > > ACPI provides no guarantees about what level of hardware functionality > > > remains during S3. You don't have any useful ability to determine which > > > events will generate wakeups. And from a purely practical point of view, > > > since the latency is in the range of seconds, you'll never have a low > > > enough wakeup rate to hit it. > > > > So PCs with current ACPI don't get opportunistic suspend capability. It > > probably won't be supported on the Commodore Amiga either - your point ? > > Actually, the reverse - there's no terribly good way to make PCs work > with scheduler-based suspend, but there's no reason why they wouldn't > work with the current opportunistic suspend implementation. How does that solve the problems you mentioned above ? Wakeup guarantees, latencies ... It's not a prove of the technical correctness of the approach if it can provide a useless functionality. Thanks, tglx