On Tue, 2013-01-15 at 19:34 +0800, Lorenzo Pieralisi wrote: > On Tue, Jan 15, 2013 at 03:00:44AM +0000, Joseph Lo wrote: > > On Fri, 2013-01-11 at 20:24 +0800, Lorenzo Pieralisi wrote: > > > On Fri, Jan 11, 2013 at 07:20:29AM +0000, Joseph Lo wrote: > > > > On Wed, 2012-12-05 at 18:50 +0800, Lorenzo Pieralisi wrote: > > > > > On Wed, Dec 05, 2012 at 10:01:49AM +0000, Joseph Lo wrote: > > > > You did mention there is an ARM generic locking scheme for MMU/coherency > > > > off case before. Do you mean the patch below? > > > > > > > > https://patchwork.kernel.org/patch/1957911/ > > > > https://patchwork.kernel.org/patch/1957901/ > > > > > > Those are used for first-man election when multiple CPUs come out of > > > idle at once. > > > > > > You should have a look at the entire series and in particular: > > > > > > https://patchwork.kernel.org/patch/1957891/ > > > https://patchwork.kernel.org/patch/1957951/ > > > > > > > I gave it a review today. Looks it can't fit our usage for CPU idle > > > > powered-down mode on Tegra20. > > > > > > > > The generic mechanism only can be used when CPUs in non coherent world. > > > > But our usage needs the mechanism could be used in both coherent and non > > > > coherent case. OK. The case is we need to sync the status about the CPU1 > > > > was ready to power down. In this case, the CPU0 is still in coherent > > > > world but the CPU1 isn't. So we need the locking scheme could be still > > > > safe in this situation. > > > > > > I know, I implemented something of that sort for an A9 based development > > > platform, that's why I pointed you to this new patchset. > > > > > > Have a look at the series, it should do what you want. > > > > > Hi Lorenzo, > > > > May I upstream this stuff first? I can promise to you I will re-work a > > common CPUs and cluster power sync wrappers (platform_power_ops) for all > > Tegra series that based on the generic framework. Because we didn't have > > this work in Tegra tree yet and we indeed need it for supporting cluster > > power down and switching. > > > > But it need lots of time for re-work, testing and verification. And I > > have lots of patches that need the function of cpu suspend that be > > introduced in this patch series to support platform suspend for Tegra. > > > > So I am asking the permission here for upstream this series first and I > > will continue the job to come out a common CPUs and cluster power sync > > wrappers for Tegra that we indeed need it to support cluster power down > > and switching. > > I understand that and you should not ask me permission :-) since I am > not a maintainer. I just wanted to save you some effort, you will end > up rewriting the whole thing anyway IMHO and I think the power API would > have saved you time if it were there before. > I think we are always taking care the comments from the community. And it's really worth for us to reconsider the code design and re-use the common framework to reduce the effort. > > If you need help to integrate the power API please do ask questions. > Thanks again. Joseph -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
