From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: Ottawa Linux Power Management Summit, June 25-26, 2007 - Minutes Date: Tue, 25 Sep 2007 14:00:41 +0200 Message-ID: <1190721641.4035.311.camel@chaos> References: <200709050426.04793.lenb@kernel.org> <200709091426.39854.rjw@sisk.pl> <20070924194102.GH8127@redhat.com> <200709251339.37601.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200709251339.37601.rjw@sisk.pl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: "Rafael J. Wysocki" Cc: linux-pm@lists.linux-foundation.org List-Id: linux-pm@vger.kernel.org On Tue, 2007-09-25 at 13:39 +0200, Rafael J. Wysocki wrote: > On Monday, 24 September 2007 21:41, Dave Jones wrote: > > On Sun, Sep 09, 2007 at 02:26:39PM +0200, Rafael J. Wysocki wrote: > > > > > > Dave mentioned that Fedora Core 7 32-bit is now shipping with > > > > CONFIG_NOHZ=y and CONFIG_HZ=1000. > > > > > > CONFIG_NOHZ is known to break suspend and resume on some machines. These > > > problems are being fixed over time, but that's a risky decision for a > > > distribution to switch it on by default. > > > > Expect to see everyone else doing the same thing in the next versions. > > Without field-testing this stuff it remains busted. A lot of bugs got > > found and fixed by having this in Fedora that weren't tripped over > > by linux-kernel testers at all. > > Well, that's certainly true. > > Still, we have open suspend bugs in which NO_HZ appears to be the culprit, > eg. http://bugzilla.kernel.org/show_bug.cgi?id=8680 Grr, kernel.org bugzilla is down. I take a look later. Btw. I got an interesting private response to the latest ACPI fixes: > > ACPI: disable lower idle C-states across suspend/resume > > > > Finally, the weird suspend/resume behavior of my Dell-420 laptop has > > disapeared (no way to adjust brightness after a suspend when not in the > > docking station). It was always dark after a resume and made the laptop > > unuseable in practice. > > I cheered too early: > I just discovered that suspending to ram works well for the first time, > but after that it's still the same problem. Suspend to disk always > worked well btw. But somehow there is a difference now: when switching > to a normal console (ctrl-alt-F1 e.g.) and switching back to X the > brightness works again. Another thing: I now can also suspend *in* the > docking station, take it *out* and resume without problems, which never > worked before :) Len, did you / Venki look into a similar solution for cpuidle yet ? I'd like to update -hrt ASAP. If not I just hack it in for now. tglx