From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753363AbbGXFu7 (ORCPT ); Fri, 24 Jul 2015 01:50:59 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:55822 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200AbbGXFu4 (ORCPT ); Fri, 24 Jul 2015 01:50:56 -0400 Date: Fri, 24 Jul 2015 07:50:38 +0200 From: Sascha Hauer To: Scott Shu Cc: yingjoe.chen@mediatek.com, robh+dt@kernel.org, matthias.bgg@gmail.com, linux@arm.linux.org.uk, rchintakuntla@cavium.com, lorenzo.pieralisi@arm.com, marc.ceeeee@gmail.com, heiko@sntech.de, catalin.marinas@arm.com, arnd@arndb.de, galak@codeaurora.org, srv_wsdupstream@mediatek.com, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loda.chou@mediatek.com, jades.shih@mediatek.com, scott.shu@gmail.com Subject: Re: [RESEND PATCH 2/6] soc: Mediatek: Add SCPSYS CPU power domain driver Message-ID: <20150724055038.GJ18700@pengutronix.de> References: <1434650481-39421-1-git-send-email-scott.shu@mediatek.com> <1434650481-39421-3-git-send-email-scott.shu@mediatek.com> <20150623055351.GA22419@pengutronix.de> <1437703323.11272.12.camel@mtkswgap22> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437703323.11272.12.camel@mtkswgap22> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-IRC: #ptxdist @freenode X-Accept-Language: de,en X-Accept-Content-Type: text/plain X-Uptime: 07:35:20 up 28 days, 23:56, 50 users, load average: 0.43, 0.25, 0.21 User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 24, 2015 at 10:02:03AM +0800, Scott Shu wrote: > On Tue, 2015-06-23 at 07:53 +0200, Sascha Hauer wrote: > > Hi Scott, > > > > On Fri, Jun 19, 2015 at 02:01:17AM +0800, Scott Shu wrote: > > > This adds a CPU power domain driver for the Mediatek SCPSYS unit on > > > MT6580. > > > > This seems to be support for the very same hardware as I am posting > > here: > > > > https://lkml.org/lkml/2015/6/22/41 > > > > We should consolidate this. > > > > My driver is currently handles all power domains except the CPUs while > > yours handles only the CPUs. > > I currently haven't looked whether CPUs can just be part of a power > > domain aswell, but if that works this would probably be the way to go. > > > > Sascha > > > > > Hi Sascga, > > We had posted new patch set in following link, but still keep our > original framework. > http://lists.infradead.org/pipermail/linux-mediatek/2015-July/001498.html > > As we mentioned in the new email thread, the SMP operations (smp_boot_secondary) > will be executed before registering the scpsys_drv driver, so the CPUs power > domain is controlled on arch/arm/mach-$(MACHINE) directory. > > Please kindly provide your comments and suggestion. Thank you very much. I think that instead of explaining why have to duplicate the code you should rather search for ways how the code can be shared. Yes, we'll need a second (early) entry point to the driver. Maybe we even have to create the shared code which is then called from the driver and your early architecture code. You'll probably have to do this separation between early code and regular driver code in your driver anyway, since I bet the MT6580 also has some power domains which shall be controlled by the regular Linux power domain code later. Also we probably could control the CPU power domains for the MT8173 in the SCPSYS driver aswell, we just don't have to because we use PSCI there. You see we are approaching the same problem from two different corners. Let's find a way to share the code. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | From mboxrd@z Thu Jan 1 00:00:00 1970 From: s.hauer@pengutronix.de (Sascha Hauer) Date: Fri, 24 Jul 2015 07:50:38 +0200 Subject: [RESEND PATCH 2/6] soc: Mediatek: Add SCPSYS CPU power domain driver In-Reply-To: <1437703323.11272.12.camel@mtkswgap22> References: <1434650481-39421-1-git-send-email-scott.shu@mediatek.com> <1434650481-39421-3-git-send-email-scott.shu@mediatek.com> <20150623055351.GA22419@pengutronix.de> <1437703323.11272.12.camel@mtkswgap22> Message-ID: <20150724055038.GJ18700@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Jul 24, 2015 at 10:02:03AM +0800, Scott Shu wrote: > On Tue, 2015-06-23 at 07:53 +0200, Sascha Hauer wrote: > > Hi Scott, > > > > On Fri, Jun 19, 2015 at 02:01:17AM +0800, Scott Shu wrote: > > > This adds a CPU power domain driver for the Mediatek SCPSYS unit on > > > MT6580. > > > > This seems to be support for the very same hardware as I am posting > > here: > > > > https://lkml.org/lkml/2015/6/22/41 > > > > We should consolidate this. > > > > My driver is currently handles all power domains except the CPUs while > > yours handles only the CPUs. > > I currently haven't looked whether CPUs can just be part of a power > > domain aswell, but if that works this would probably be the way to go. > > > > Sascha > > > > > Hi Sascga, > > We had posted new patch set in following link, but still keep our > original framework. > http://lists.infradead.org/pipermail/linux-mediatek/2015-July/001498.html > > As we mentioned in the new email thread, the SMP operations (smp_boot_secondary) > will be executed before registering the scpsys_drv driver, so the CPUs power > domain is controlled on arch/arm/mach-$(MACHINE) directory. > > Please kindly provide your comments and suggestion. Thank you very much. I think that instead of explaining why have to duplicate the code you should rather search for ways how the code can be shared. Yes, we'll need a second (early) entry point to the driver. Maybe we even have to create the shared code which is then called from the driver and your early architecture code. You'll probably have to do this separation between early code and regular driver code in your driver anyway, since I bet the MT6580 also has some power domains which shall be controlled by the regular Linux power domain code later. Also we probably could control the CPU power domains for the MT8173 in the SCPSYS driver aswell, we just don't have to because we use PSCI there. You see we are approaching the same problem from two different corners. Let's find a way to share the code. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |