From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh Shilimkar) Date: Fri, 03 Jun 2011 10:56:29 +0530 Subject: [GIT PULL] scalable TWD localtimer In-Reply-To: References: Message-ID: <4DE87085.1090901@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Linus, On 6/3/2011 3:31 AM, Linus Walleij wrote: > Hi Russell, > > please consider pulling this for the -rc series since I see this as a > horrible bug that Thomas just fixed the infrastructure to properly > counter the week before the merge window. > > You probably know the story but basically there is one clockline > into the ARM-supplied MPCore thing, and it inevitably also clocks > the TWD. Sadly that includes the localtimer, which will make all > clockevents scale in both directions, firing too late or too early > as compared to desired wall-clock time (or system clocksource) as > the clock speed of the core is changed. Right now there is no > compensation whatsoever for this so to run the system reliably > on v3.0-rc1, cpufreq has to be disabled. > > Thomas and Colin did the grunt work, I added a scaling smp_twd > clock reflecting the Ux500 cpufreq changes, and now it is rock solid > as far as I can tell. > Hope the pull is already not done. If not I would like to submit the OMAP clock change as well along with this series and may be Colin might want to do the same for Tegra. Regards Santosh