Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932490AbcDLILt (ORCPT ); Tue, 12 Apr 2016 04:11:49 -0400 Received: from mailout4.w1.samsung.com ([210.118.77.14]:51048 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932200AbcDLILl (ORCPT ); Tue, 12 Apr 2016 04:11:41 -0400 X-AuditID: cbfec7f4-f796c6d000001486-f4-570ca41c3974 Subject: Re: [PATCH v9 05/20] PM / devfreq: Add new passive governor To: Chanwoo Choi , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, kgene@kernel.org, s.nawrocki@samsung.com, tomasz.figa@gmail.com References: <1460347078-15175-1-git-send-email-cw00.choi@samsung.com> <1460347078-15175-6-git-send-email-cw00.choi@samsung.com> Cc: rjw@rjwysocki.net, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux@arm.linux.org.uk, linux.amoon@gmail.com, m.reichl@fivetechno.de, tjakobi@math.uni-bielefeld.de, inki.dae@samsung.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org From: Krzysztof Kozlowski Message-id: <570CA41A.5050500@samsung.com> Date: Tue, 12 Apr 2016 09:30:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-version: 1.0 In-reply-to: <1460347078-15175-6-git-send-email-cw00.choi@samsung.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrJIsWRmVeSWpSXmKPExsVy+t/xy7oyS3jCDaZfELO4/uU5q8X8I+dY LfrfLGS1OPdqJaPFpPsTWCxevzC06H/8mtnibNMbdotNj6+xWlzeNYfN4nPvEUaLGef3MVms 23iL3eL2ZV6Ll0d+MFosvX6RyeJ24wo2iwnT17JYnDl9idWide8RdovDb9pZLdpWf2C1WLXr D6ODuMeaeWsYPVqae9g8Lvf1MnnculPvsXPWXXaPlcu/sHlsWtXJ5rF5Sb3Hv2PsHluutrN4 9G1ZxejxeZNcAE8Ul01Kak5mWWqRvl0CV8aSvevYC/4KVOyeuJG5gfEVbxcjJ4eEgInE7yd9 bBC2mMSFe+vBbCGBpYwSU5bLdTFyAdnPGCVuXFkFlODgEBZwkVhyowQkLiKwiFFi88J2Zoii RkaJtmWLGUEcZoG1zBKv2htZQUaxCRhLbF6+BGwsr4CWxKm5s8BsFgFVie+/vzOD2KICERJP 5p5khKgRlPgx+R4LiM0p4Caxtf892GZmAT2J+xe1QMLMAvISm9e8ZZ7AKDALSccshKpZSKoW MDKvYhRNLU0uKE5KzzXUK07MLS7NS9dLzs/dxAiJ4C87GBcfszrEKMDBqMTD+8CZJ1yINbGs uDL3EKMEB7OSCO+N+UAh3pTEyqrUovz4otKc1OJDjNIcLErivHN3vQ8REkhPLEnNTk0tSC2C yTJxcEo1MOY5629vCI/6G3Ph3p7vq0rr98XVr1zx8zjj6udCJz9Nm7r4n+6CH/dtvSwLny+f zz0rMXJPbNpkzcOND5x2nn5zrOzpbme/FUtmuO8NY7bvYJmS/tZVZDnTe76VSvPv1+oferDp xZN7tydLS5+vfsixtZthzhUe1Q8uPP9tv3Gtcfp16or9tu9GSizFGYmGWsxFxYkA2uNLcdwC AAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2127 Lines: 44 On 04/11/2016 05:57 AM, Chanwoo Choi wrote: > This patch adds the new passive governor for DEVFREQ framework. The following > governors are already present and used for DVFS (Dynamic Voltage and Frequency > Scaling) drivers. The following governors are independently used for one device > driver which don't give the influence to other device drviers and also don't > receive the effect from other device drivers. > - ondemand / performance / powersave / userspace > > The passive governor depends on operation of parent driver with specific > governos extremely and is not able to decide the new frequency by oneself. > According to the decided new frequency of parent driver with governor, > the passive governor uses it to decide the appropriate frequency for own > device driver. The passive governor must need the following information > from device tree: > - the source clock and OPP tables > - the instance of parent device > > For exameple, > there are one more devfreq device drivers which need to change their source > clock according to their utilization on runtime. But, they share the same > power line (e.g., regulator). So, specific device driver is operated as parent > with ondemand governor and then the rest device driver with passive governor > is influenced by parent device. > > Suggested-by: Myungjoo Ham > Signed-off-by: Chanwoo Choi > [tjakobi: Reported RCU locking issue and cw00.choi fix it] > Reported-by: Tobias Jakobi > [linux.amoon: Reported possible recursive locking and cw00.choi fix it] > Reported-by: Anand Moon > Signed-off-by: MyungJoo Ham > --- > drivers/devfreq/Kconfig | 8 ++ > drivers/devfreq/Makefile | 1 + > drivers/devfreq/governor_passive.c | 207 +++++++++++++++++++++++++++++++++++++ > include/linux/devfreq.h | 33 ++++++ > 4 files changed, 249 insertions(+) > create mode 100644 drivers/devfreq/governor_passive.c > Acked-by: Krzysztof Kozlowski Best regards, Krzysztof