From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz Date: Wed, 2 Aug 2017 09:19:51 +0530 Message-ID: <20170802034951.GA31169@vireshk-i7> References: <1501230993-15812-1-git-send-email-sebastien.szymanski@armadeus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Received: from mail-pg0-f46.google.com ([74.125.83.46]:35988 "EHLO mail-pg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751696AbdHBDty (ORCPT ); Tue, 1 Aug 2017 23:49:54 -0400 Received: by mail-pg0-f46.google.com with SMTP id v77so10300981pgb.3 for ; Tue, 01 Aug 2017 20:49:54 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1501230993-15812-1-git-send-email-sebastien.szymanski@armadeus.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Shawn Guo , =?iso-8859-1?Q?S=E9bastien?= Szymanski Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Fabio Estevam , Julien Boibessot On 28-07-17, 10:36, Sébastien Szymanski wrote: > Setting the frequency higher than 528Mhz actually sets the ARM > clock to 528MHz. That's because PLL2 is used as the root clock when the > frequency is higher than 396MHz. > > cpupower frequency-set -f 792000 > > arm_clk_root on the CCM_CLKO2 signal is 528MHz instead of 792MHz. > > [ 61.606383] cpu cpu0: 396 MHz, 1025 mV --> 792 MHz, 1225 mV > > pll2 1 1 528000000 0 0 > pll2_bypass 1 1 528000000 0 0 > pll2_bus 3 3 528000000 0 0 > ca7_secondary_sel 1 1 528000000 0 0 > step 1 1 528000000 0 0 > pll1_sw 1 1 528000000 0 0 > arm 1 1 528000000 0 0 > > Fixes this by using the PLL1 as the root clock when the frequency is > higher than 528MHz. > > cpupower frequency-set -f 792000 > > arm_clk_root on the CCM_CLKO2 signal is now 792MHz as expected. > > [ 69.717987] cpu cpu0: 198 MHz, 950 mV --> 792 MHz, 1225 mV > > pll1 1 1 792000000 0 0 > pll1_bypass 1 1 792000000 0 0 > pll1_sys 1 1 792000000 0 0 > pll1_sw 1 1 792000000 0 0 > arm 1 1 792000000 0 0 > > Signed-off-by: Sébastien Szymanski > --- > drivers/cpufreq/imx6q-cpufreq.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) Looks fine to me: Acked-by: Viresh Kumar @Shawn: Can you also confirm if this looks fine to you ? -- viresh