From patchwork Thu Sep 24 12:30:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ionela Voinescu X-Patchwork-Id: 11797169 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D4CE66CB for ; Thu, 24 Sep 2020 12:30:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2CC0235FD for ; Thu, 24 Sep 2020 12:30:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727795AbgIXMaz (ORCPT ); Thu, 24 Sep 2020 08:30:55 -0400 Received: from foss.arm.com ([217.140.110.172]:44636 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727561AbgIXMay (ORCPT ); Thu, 24 Sep 2020 08:30:54 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 566EB113E; Thu, 24 Sep 2020 05:30:54 -0700 (PDT) Received: from e108754-lin.cambridge.arm.com (unknown [10.1.199.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C202A3F73B; Thu, 24 Sep 2020 05:30:52 -0700 (PDT) From: Ionela Voinescu To: catalin.marinas@arm.com, sudeep.holla@arm.com, will@kernel.org, linux@armlinux.org.uk, rjw@rjwysocki.net, viresh.kumar@linaro.org Cc: dietmar.eggemann@arm.com, valentin.schneider@arm.com, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, ionela.voinescu@arm.com Subject: [PATCH 2/2] arm: disable frequency invariance for CONFIG_BL_SWITCHER Date: Thu, 24 Sep 2020 13:30:16 +0100 Message-Id: <20200924123016.13427-3-ionela.voinescu@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200924123016.13427-1-ionela.voinescu@arm.com> References: <20200924123016.13427-1-ionela.voinescu@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org big.LITTLE switching complicates the setting of a correct cpufreq-based frequency invariance scale factor due to (as observed in drivers/cpufreq/vexpress-spc-cpufreq.c): - Incorrect current and maximum frequencies as a result of the exposure of a virtual frequency table to the cpufreq core, - Missed updates as a result of asynchronous frequency adjustments caused by frequency changes in other CPU pairs. Given that its functionality is atypical in regards to frequency invariance and this is an old technology, disable frequency invariance for when big.LITTLE switching is configured in to prevent incorrect scale setting. Signed-off-by: Ionela Voinescu Suggested-by: Dietmar Eggemann Cc: Russell King Cc: Catalin Marinas Acked-by: Viresh Kumar --- arch/arm/include/asm/topology.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index e5e3d5ce4d55..470299ee2fba 100644 --- a/arch/arm/include/asm/topology.h +++ b/arch/arm/include/asm/topology.h @@ -7,10 +7,13 @@ #include #include +/* big.LITTLE switcher is incompatible with frequency invariance */ +#ifndef CONFIG_BL_SWITCHER /* Replace task scheduler's default frequency-invariant accounting */ #define arch_set_freq_scale topology_set_freq_scale #define arch_scale_freq_capacity topology_get_freq_scale #define arch_scale_freq_invariant topology_scale_freq_invariant +#endif /* Replace task scheduler's default cpu-invariant accounting */ #define arch_scale_cpu_capacity topology_get_cpu_scale