From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko =?ISO-8859-1?Q?St=FCbner?= Subject: Re: [PATCH] ARM: dts: rockchip: Add dynamic-power-coefficient for rk3288 Date: Fri, 12 Apr 2019 12:08:21 +0200 Message-ID: <9063550.zi1cCdPW0A@diego> References: <20190412000158.248080-1-mka@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <20190412000158.248080-1-mka@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Matthias Kaehlcke Cc: Rob Herring , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Douglas Anderson List-Id: linux-rockchip.vger.kernel.org Am Freitag, 12. April 2019, 02:01:58 CEST schrieb Matthias Kaehlcke: > The value was determined with the following method: > > - take CPUs 1-3 offline > - for each OPP > - set cpufreq min and max freq to OPP freq > - start dhrystone benchmark > - measure CPU power consumption during 10s > - calculate Cx for OPPx > - Cx = (Px - P1) / (Vx²fx - V1²f1) [1] > using the following units: mW / Ghz / V [2] > - C = avg(C2, ..., Cn) > > [1] see commit 4daa001a1773 ("arm64: dts: juno: Add cpu > dynamic-power-coefficient information") > [2] https://patchwork.kernel.org/patch/10493615/#22158551 > > FTR, these are the values for the different OPPs: > > freq (kHz) mV Px (mW) Cx > > 126000 900 39 > 216000 900 66 370 > 312000 900 95 372 > 408000 900 122 363 > 600000 900 177 359 > 696000 950 230 363 > 816000 1000 297 361 > 1008000 1050 404 362 > 1200000 1100 528 362 > 1416000 1200 770 377 > 1512000 1300 984 385 > 1608000 1350 1156 394 > > Signed-off-by: Matthias Kaehlcke I've applied this for 5.2 but moved the new entries below the clock properties for some more alphabetic ordering. Heiko