From mboxrd@z Thu Jan 1 00:00:00 1970 From: andrew-sh.cheng Subject: Re: [PATCH v2 4/4] devfreq: add mediatek cci devfreq Date: Sat, 13 Apr 2019 13:54:28 +0800 Message-ID: <1555134868.14109.11.camel@mtksdaap41> References: <1553841972-19737-5-git-send-email-andrew-sh.cheng@mediatek.com> <1553841972-19737-1-git-send-email-andrew-sh.cheng@mediatek.com> <20190401041843epcms1p10a664023cf0556e42afe118a1d84daad@epcms1p1> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190401041843epcms1p10a664023cf0556e42afe118a1d84daad@epcms1p1> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: myungjoo.ham@samsung.com Cc: Mark Rutland , "devicetree@vger.kernel.org" , "srv_heupstream@mediatek.com" , "linux-pm@vger.kernel.org" , Viresh Kumar , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Chanwoo Choi , Kyungmin Park , Rob Herring , "linux-mediatek@lists.infradead.org" , Matthias Brugger , "fan.chen@mediatek.com" , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Mon, 2019-04-01 at 13:18 +0900, MyungJoo Ham wrote: > >This adds a devfreq driver for the Cache Coherent Interconnect (CCI) > >of the Mediatek MT8183. > > > >On the MT8183 the CCI is supplied by the same regulator as the LITTLE > >cores. The driver is notified when the regulator voltage changes > >(driven by cpufreq) and adjusts the CCI frequency to the maximum > >possible value. > > > >Signed-off-by: Andrew-sh.Cheng > >--- > > drivers/devfreq/Kconfig | 10 ++ > > drivers/devfreq/Makefile | 1 + > > drivers/devfreq/mt8183-cci-devfreq.c | 235 +++++++++++++++++++++++++++++++++++ > > 3 files changed, 246 insertions(+) > > create mode 100644 drivers/devfreq/mt8183-cci-devfreq.c > > > > 1. It appears that proc_reg_uV might be used before initialization. > It would be appropriate to initialize it at the probe function. In this governor, cci only change frequency after get notification. So it must set proc_reg_uV first, and then call update_devfreq() which call to mtk_cci_governor_get_target() and use proc_reg_uV. > > 2. Because you are already using OPP, why don't you rely on > OPP fully? (use OPP from CPUFreq drivers as well in order to get > OPP events automatically.) Anyway, this is a minor item that does > not need to be corrected. For some discuss about this in Mediatek before, we decide to put the operation of CCI in CCI related driver and separated from CPUFreq. > > Cheers > MyungJoo > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek