From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938099AbdAFIEb (ORCPT ); Fri, 6 Jan 2017 03:04:31 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:38592 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751155AbdAFIEX (ORCPT ); Fri, 6 Jan 2017 03:04:23 -0500 Subject: Re: [PATCH] ARM64: dts: meson-gxbb-odroidc2: Disable SCPI DVFS To: =?UTF-8?Q?Micha=c5=82_Zegan?= , khilman@baylibre.com, carlo@caione.org References: <1483628549-29486-1-git-send-email-narmstrong@baylibre.com> <9f508097-f605-ebd8-20af-c3e798c6fdcc@poczta.onet.pl> Cc: linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Neil Armstrong Organization: Baylibre Message-ID: Date: Fri, 6 Jan 2017 09:04:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <9f508097-f605-ebd8-20af-c3e798c6fdcc@poczta.onet.pl> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="GmkxHMmbqVGV8bILqPhq3BXoJXvobHSAC" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --GmkxHMmbqVGV8bILqPhq3BXoJXvobHSAC Content-Type: multipart/mixed; boundary="DMLGPPfTJcxRsBMCfIkd3ogD3sVUcpFT1"; protected-headers="v1" From: Neil Armstrong To: =?UTF-8?Q?Micha=c5=82_Zegan?= , khilman@baylibre.com, carlo@caione.org Cc: linux-amlogic@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Message-ID: Subject: Re: [PATCH] ARM64: dts: meson-gxbb-odroidc2: Disable SCPI DVFS References: <1483628549-29486-1-git-send-email-narmstrong@baylibre.com> <9f508097-f605-ebd8-20af-c3e798c6fdcc@poczta.onet.pl> In-Reply-To: <9f508097-f605-ebd8-20af-c3e798c6fdcc@poczta.onet.pl> --DMLGPPfTJcxRsBMCfIkd3ogD3sVUcpFT1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 01/05/2017 08:04 PM, Micha=C5=82 Zegan wrote: > Hello. >=20 > The patch causes cpufreq module (scpi-cpufreq) not to detect cpufreq, s= o > it actually works, but... > Loading the module causes few errors because of not found frequencies o= r > something, then it is all okay. However after loading scpi-cpufreq you > cannot actually power the cpu off and on. You will power it off > successfully, but when trying to power it on, the cpufreq driver will > error out, and then after it happens, the cpu that was trying to go > online will be offline again, and that is a little... unfortunate. The > question is, and I cannot really test that: will the module actually > autoload after this change? Hi Michal, You are right, it breaks cpufreq and the cpu hotplug feature, I will send= a v2 completely disabling cpufreq instead. For the module autoloading, the arm_scpi.ko must be loaded before the oth= er scpi modules. Please ask Sudeep Holla if module autoloading for = scpi is meant to work. Neil >=20 > W dniu 05.01.2017 o 16:02, Neil Armstrong pisze: >> The current hardware is not able to run with all cores enabled at a >> cluster frequency superior at 1536MHz. >> But the currently shipped u-boot for the platform still reports an OPP= >> table with possible DVFS frequency up to 2GHz, and will not change sin= ce >> the off-tree linux tree supports limiting the OPPs with a kernel param= eter. >> A recent u-boot change reports the boot-time DVFS around 100MHz and >> the default performance cpufreq governor sets the maximum frequency. >> Previous version of u-boot reported to be already at the max OPP and >> left the OPP as is. >> Nevertheless, other governors like ondemand could setup the max freque= ncy >> and make the system crash. >> >> This patch disables the DVFS clock and disables cpufreq. >> >> Fixes: 70db166a2baa ("ARM64: dts: meson-gxbb: Add SCPI with cpufreq & = sensors Nodes") >> Signed-off-by: Neil Armstrong >> --- >> arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts b/arc= h/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts >> index 238fbea..5e63e3b 100644 >> --- a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts >> +++ b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts >> @@ -137,6 +137,10 @@ >> }; >> }; >> =20 >> +&scpi_dvfs { >> + status =3D "disabled"; >> +}; >> + >> &uart_AO { >> status =3D "okay"; >> pinctrl-0 =3D <&uart_ao_a_pins>; >> >=20 --DMLGPPfTJcxRsBMCfIkd3ogD3sVUcpFT1-- --GmkxHMmbqVGV8bILqPhq3BXoJXvobHSAC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJYb0+CAAoJEHfc29rIyEnRHP0QAMsWL4KefWjP52x6Nsn6lB9P GmTSDy5iReWwr40c1G4ZqhGPS9OnC4fuIUJFNeK47C2X7dQe2FhEx7wbqRAcvTAP eH94xriMA+8ZY2xkoew2VAKYGuoDawKYjZPGGTQJHwpobAySeoLaAWGeGwewW0+9 plBcuFKnPXWUKWf00QmjFOBLgwuGXRpeakfT4lcdNDrHnIjfa9M4SgBA/gtzJl+L y/30G1eqVInpc+eNN6uwAj4OpCPXXJg3LDsdU4+xB4lGFUi6gqcAstyHnZIo/cKX wfL5t/E1MO7McAbsLlquySLkF53I6o2hNm29phFk5YqA0UO2KDJw/J490ocpUx4l I/rZMNAGh8hw0TnkvrJiepETovokeR41J8d4QcJTrnYOcKONVWHFK5sLaC44MqjW cX2SCmukiYENSnxUv07kkRuX7nDRJSHxE6cw/vK3qtloJ39SZpZbY3Q2i0HIuvmB 1ibHDOx1JR61jPwS/uWuSL1l0EFA3hl+/O1z5J6/LJeqMbxCzI1v+nbnmFu80ib7 GVc/7g5x3QIUvVkFL72HDczbbfyLdTUmKGWtxYSNZ/pDmIQlz/CDr5fXfEFpPJzx oHPbq4apA7qK7vBjkTy0IJxM8bWPs5HKT44C1W+QIQwlLuOs/EJDlH3ODqdCIfbi twnEtr2huaksQmXv8tJg =MA/2 -----END PGP SIGNATURE----- --GmkxHMmbqVGV8bILqPhq3BXoJXvobHSAC--