From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6194C25B41 for ; Mon, 23 Oct 2023 08:53:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232310AbjJWIxa (ORCPT ); Mon, 23 Oct 2023 04:53:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60576 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229463AbjJWIx2 (ORCPT ); Mon, 23 Oct 2023 04:53:28 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0DFBCA9; Mon, 23 Oct 2023 01:53:24 -0700 (PDT) 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 6349C2F4; Mon, 23 Oct 2023 01:54:05 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AF9893F64C; Mon, 23 Oct 2023 01:53:22 -0700 (PDT) Date: Mon, 23 Oct 2023 09:53:20 +0100 From: Sudeep Holla To: Sumit Gupta Cc: , , , , , , , , , , , , Subject: Re: [Patch v5 2/2] ACPI: processor: reduce CPUFREQ thermal reduction pctg for Tegra241 Message-ID: References: <20231014105426.26389-1-sumitg@nvidia.com> <20231014105426.26389-3-sumitg@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231014105426.26389-3-sumitg@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 14, 2023 at 04:24:26PM +0530, Sumit Gupta wrote: > From: Srikar Srimath Tirumala > > Current implementation of processor_thermal performs software throttling > in fixed steps of "20%" which can be too coarse for some platforms. > We observed some performance gain after reducing the throttle percentage. > Change the CPUFREQ thermal reduction percentage and maximum thermal steps > to be configurable. Also, update the default values of both for Nvidia > Tegra241 (Grace) SoC. The thermal reduction percentage is reduced to "5%" > and accordingly the maximum number of thermal steps are increased as they > are derived from the reduction percentage. > > Signed-off-by: Srikar Srimath Tirumala > Co-developed-by: Sumit Gupta > Signed-off-by: Sumit Gupta > --- > drivers/acpi/arm64/Makefile | 1 + > drivers/acpi/arm64/thermal_cpufreq.c | 20 ++++++++++++++++ > drivers/acpi/processor_thermal.c | 35 +++++++++++++++++++++++++--- > include/linux/acpi.h | 9 +++++++ > 4 files changed, 62 insertions(+), 3 deletions(-) > create mode 100644 drivers/acpi/arm64/thermal_cpufreq.c > > diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile > index 143debc1ba4a..3f181d8156cc 100644 > --- a/drivers/acpi/arm64/Makefile > +++ b/drivers/acpi/arm64/Makefile > @@ -5,3 +5,4 @@ obj-$(CONFIG_ACPI_GTDT) += gtdt.o > obj-$(CONFIG_ACPI_APMT) += apmt.o > obj-$(CONFIG_ARM_AMBA) += amba.o > obj-y += dma.o init.o > +obj-$(CONFIG_ACPI) += thermal_cpufreq.o Do we really need CONFIG_ACPI here ? We won't be building this if it is not enabled. If this is for some module building, then does it make sense to have more specific config ? May be CONFIG_ACPI_THERMAL ? > diff --git a/drivers/acpi/arm64/thermal_cpufreq.c b/drivers/acpi/arm64/thermal_cpufreq.c > new file mode 100644 > index 000000000000..de834fb013e7 > --- /dev/null > +++ b/drivers/acpi/arm64/thermal_cpufreq.c > @@ -0,0 +1,20 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +#include > + > +#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY > +#define SMCCC_SOC_ID_T241 0x036b0241 > + > +int acpi_thermal_cpufreq_pctg(void) > +{ > + s32 soc_id = arm_smccc_get_soc_id_version(); > + > + /* > + * Check JEP106 code for NVIDIA Tegra241 chip (036b:0241) and > + * reduce the CPUFREQ Thermal reduction percentage to 5%. > + */ > + if (soc_id == SMCCC_SOC_ID_T241) > + return 5; > + > + return 0; > +} > +#endif Since this looks like arch specific hook/callback, not sure if it is good idea to have "arch_" in the function name. But if Rafael is OK with the name I am fine with this as well. -- Regards, Sudeep