From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH v7] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420 Date: Tue, 8 Jul 2014 16:19:24 +0100 Message-ID: <20140708151924.GF24915@e102568-lin.cambridge.arm.com> References: <1404496024-7113-1-git-send-email-a.kesavan@samsung.com> <1404503133-19760-1-git-send-email-a.kesavan@samsung.com> <20140708105351.GA24915@e102568-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Return-path: Received: from service87.mimecast.com ([91.220.42.44]:42923 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750707AbaGHPT2 convert rfc822-to-8bit (ORCPT ); Tue, 8 Jul 2014 11:19:28 -0400 In-Reply-To: Content-Disposition: inline Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Abhilash Kesavan Cc: Nicolas Pitre , linux-samsung-soc , linux-arm-kernel , Kukjin Kim , Andrew Bresticker , Douglas Anderson On Tue, Jul 08, 2014 at 02:39:37PM +0100, Abhilash Kesavan wrote: > Hi Lorenzo, > > On Tue, Jul 8, 2014 at 4:23 PM, Lorenzo Pieralisi > wrote: > > On Fri, Jul 04, 2014 at 10:21:56PM +0100, Abhilash Kesavan wrote: > >> On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre wrote: > >> > On Sat, 5 Jul 2014, Abhilash Kesavan wrote: > >> > > >> >> Use the MCPM layer to handle core suspend/resume on Exynos5420. > >> >> Also, restore the entry address setup code post-resume. > >> >> > >> >> Signed-off-by: Abhilash Kesavan > >> > > >> > Acked-by: Nicolas Pitre > >> This is one of the last missing bits for exynos MCPM. Thanks for your > >> patient reviews of all the exynos mcpm back-end patches. > > > > Sorry for the delay in getting back to you. > Thanks for your comments. > > > > You still need to handle the residency parameter in the MCPM suspend call > > properly to differentiate between core gating and cluster gating. > I am not too familiar with the cpuidle driver, but I see only cluster > power off state listed in the bL cpuidle driver. > > > > CPUidle might want to request a state that allows for core gating > > residency but not cluster gating one, in that case the last man > > standing must not shutdown the cluster. > For this, I would have to add another state to the bL cpuidle driver > or migrate to using your under-review generic idle state patchset. > Then based on the residency value skip/do cluster power down. Is this > correct ? > > > > This must be handled in the power down function, and it can be done > > in a separate patch since it is an optimization. Current MCPM interface has > > all it is needed to handle this properly, and I am keen on patching the > > CPUidle bL driver to pass the actual residency instead of hardcoding it > > to 0 (ie on TC2 it was not needed, no core gating). > I will look at doing this once the s2r patch gets merged. Ok, let's get it done once the CPUidle bL driver DT version gets merged, I will add a patch that passes the proper residency and you can patch the MCPM back-end then, until then CPUidle will be suboptimal but I guess we can live with that for now. Thanks, Lorenzo From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Tue, 8 Jul 2014 16:19:24 +0100 Subject: [PATCH v7] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420 In-Reply-To: References: <1404496024-7113-1-git-send-email-a.kesavan@samsung.com> <1404503133-19760-1-git-send-email-a.kesavan@samsung.com> <20140708105351.GA24915@e102568-lin.cambridge.arm.com> Message-ID: <20140708151924.GF24915@e102568-lin.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Jul 08, 2014 at 02:39:37PM +0100, Abhilash Kesavan wrote: > Hi Lorenzo, > > On Tue, Jul 8, 2014 at 4:23 PM, Lorenzo Pieralisi > wrote: > > On Fri, Jul 04, 2014 at 10:21:56PM +0100, Abhilash Kesavan wrote: > >> On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre wrote: > >> > On Sat, 5 Jul 2014, Abhilash Kesavan wrote: > >> > > >> >> Use the MCPM layer to handle core suspend/resume on Exynos5420. > >> >> Also, restore the entry address setup code post-resume. > >> >> > >> >> Signed-off-by: Abhilash Kesavan > >> > > >> > Acked-by: Nicolas Pitre > >> This is one of the last missing bits for exynos MCPM. Thanks for your > >> patient reviews of all the exynos mcpm back-end patches. > > > > Sorry for the delay in getting back to you. > Thanks for your comments. > > > > You still need to handle the residency parameter in the MCPM suspend call > > properly to differentiate between core gating and cluster gating. > I am not too familiar with the cpuidle driver, but I see only cluster > power off state listed in the bL cpuidle driver. > > > > CPUidle might want to request a state that allows for core gating > > residency but not cluster gating one, in that case the last man > > standing must not shutdown the cluster. > For this, I would have to add another state to the bL cpuidle driver > or migrate to using your under-review generic idle state patchset. > Then based on the residency value skip/do cluster power down. Is this > correct ? > > > > This must be handled in the power down function, and it can be done > > in a separate patch since it is an optimization. Current MCPM interface has > > all it is needed to handle this properly, and I am keen on patching the > > CPUidle bL driver to pass the actual residency instead of hardcoding it > > to 0 (ie on TC2 it was not needed, no core gating). > I will look at doing this once the s2r patch gets merged. Ok, let's get it done once the CPUidle bL driver DT version gets merged, I will add a patch that passes the proper residency and you can patch the MCPM back-end then, until then CPUidle will be suboptimal but I guess we can live with that for now. Thanks, Lorenzo