From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH] timekeeping: Move persistent clock registration code from ARM to kernel Date: Fri, 9 Jan 2015 13:59:07 +0000 Message-ID: <20150109135907.GF12942@leverpostej> References: <1415388855-35074-1-git-send-email-anatol.pomozov@gmail.com> <20141110095325.GC12126@ulmo> <20150109094913.GB27845@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150109094913.GB27845@ulmo> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Thierry Reding Cc: Thomas Gleixner , Anatol Pomozov , Stephen Warren , Daniel Lezcano , Russell King , LKML , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Tony Lindgren , John Stultz , Paul Walmsley , marc.zyngier-5wv7dgnIgG8@public.gmane.org List-Id: linux-tegra@vger.kernel.org On Fri, Jan 09, 2015 at 09:49:14AM +0000, Thierry Reding wrote: > On Sat, Nov 15, 2014 at 02:38:00AM +0100, Thomas Gleixner wrote: > > On Sat, 15 Nov 2014, Thomas Gleixner wrote: > > > On Fri, 14 Nov 2014, Anatol Pomozov wrote: > > > > On Fri, Nov 14, 2014 at 4:18 PM, Thomas Gleixner wrote: > > > > >> So what I suppose to do with my patch? If it does not work could > > > > >> anyone provide patch that removes ARM arch dependency from > > > > >> tegra20_timer.c? > > > > > > > > > > Huch? You want other people to solve your problems? > > > > > > > > This is not the point. I provided patch that fixes the issue. Other > > > > people said that they have ideas how to do it different (and better) > > > > way. So I am asking to share these ideas represented as a patch. > > > > > > That's not the way it works. > > > > > > You sent a patch to solve an problem which you are facing. > > > > > > Now the people who review the patch think that there is a better > > > approach than moving code from arm/ to the timekeeping core code. > > > > > > So it's up to you to come up with a patch which solves the problem in > > > the right way. > > > > And just for the record this whole thing is just hilarious. > > > > ARM64 selects ARM_ARCH_TIMER which registers the architected timer as > > the primary clocksource. > > > > Now that timer has the following flag set: > > > > CLOCK_SOURCE_SUSPEND_NONSTOP > > > > And that flag causes the core timekeeping code to use the clocksource > > to figure out the time which the machine spent in suspend. > > As I understand it the architected timer will be turned off along with > the rest of the CPU complex on Tegra. I'm not sure if that's specific to > Tegra or something that other SoCs may do as well. That doesn't sound right to me: the architecture specifies that the system counter must be implemented in an always-on power domain. Note that that only applies to the counter, not the timers (as the comparators can be turned off with the CPUs). Mark.