Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753304AbeAEWHf (ORCPT + 1 other); Fri, 5 Jan 2018 17:07:35 -0500 Received: from mail-ot0-f196.google.com ([74.125.82.196]:46263 "EHLO mail-ot0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753288AbeAEWH2 (ORCPT ); Fri, 5 Jan 2018 17:07:28 -0500 X-Google-Smtp-Source: ACJfBovdfYFABMVRJxl8OqYPhiIc8YnBgKPjuAZg+WeEk7RntfK2R2nVz8qCecxFu+pIqv936IUeKn7vrjXQ/JKbp60= MIME-Version: 1.0 In-Reply-To: References: <20171201222330.18863-1-jeremy.linton@arm.com> <20171201222330.18863-4-jeremy.linton@arm.com> <20171213172647.GA3316@red-moon> From: "Rafael J. Wysocki" Date: Fri, 5 Jan 2018 23:07:27 +0100 X-Google-Sender-Auth: YV42KsW8OUhBCBHXFA9OoKBjVqA Message-ID: Subject: Re: [PATCH v5 3/9] ACPI: Enable PPTT support on ARM64 To: Jeremy Linton Cc: Lorenzo Pieralisi , "Rafael J. Wysocki" , ACPI Devel Maling List , linux-arm-kernel@lists.infradead.org, Sudeep Holla , Hanjun Guo , Will Deacon , Catalin Marinas , Greg Kroah-Hartman , Viresh Kumar , Mark Rutland , Linux Kernel Mailing List , Linux PM , jhugo@codeaurora.org, wangxiongfeng2@huawei.com, Jonathan.Zhang@cavium.com, Al Stone , Jayachandran.Nair@cavium.com, austinwc@codeaurora.org, Len Brown Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Fri, Jan 5, 2018 at 10:58 PM, Jeremy Linton wrote: > Hi, > > > On 12/13/2017 11:26 AM, Lorenzo Pieralisi wrote: >> >> On Fri, Dec 01, 2017 at 04:23:24PM -0600, Jeremy Linton wrote: >>> >>> Now that we have a PPTT parser, in preparation for its use >>> on arm64, lets build it. >>> >>> Signed-off-by: Jeremy Linton >>> --- >>> arch/arm64/Kconfig | 1 + >>> drivers/acpi/Kconfig | 3 +++ >>> drivers/acpi/Makefile | 1 + >>> 3 files changed, 5 insertions(+) >>> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index a93339f5178f..e62fd1e08c1f 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -7,6 +7,7 @@ config ARM64 >>> select ACPI_REDUCED_HARDWARE_ONLY if ACPI >>> select ACPI_MCFG if ACPI >>> select ACPI_SPCR_TABLE if ACPI >>> + select ACPI_PPTT if ACPI >>> select ARCH_CLOCKSOURCE_DATA >>> select ARCH_HAS_DEBUG_VIRTUAL >>> select ARCH_HAS_DEVMEM_IS_ALLOWED >>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >>> index 46505396869e..df7aebf0af0e 100644 >>> --- a/drivers/acpi/Kconfig >>> +++ b/drivers/acpi/Kconfig >>> @@ -545,6 +545,9 @@ config ACPI_CONFIGFS >>> if ARM64 >>> source "drivers/acpi/arm64/Kconfig" >>> + >>> +config ACPI_PPTT >>> + bool >> >> >> We need to make a choice here. Either PPTT is considered ARM64 only and >> we move code and config to drivers/acpi/arm64/Kconfig or we leave it in >> drivers/acpi/pptt.c and we add a Kconfig entry in drivers/acpi/Kconfig >> (and we make pptt.c compile on !ARM64 - which is what it should be given >> that there is nothing ARM64 specific in it). > > > No one else has expressed and opinion about this here.. > > So i'm not sure what to think. > > OTOH a lot of people didn't like it when I had it in the arm64 directory, > which was my original opinion. It seems other people thought that at some > point in the future other ACPI platforms would want to use it so putting it > in the arm64 directory was a mistake. In my view it may go directly into drivers/acpi/ for the time being. That said, going forward it may be useful to add a special subdirectory under drivers/acpi/ for these "table drivers" as we seem to be acquiring them at alarming rate. > So, I'm leaning towards leaving it like it is, under the assumption that > when someone puts in the effort to verify it on another ACPI platform they > can move the config option up 6 lines. In the meantime I don't think it > should be enabled on platforms where it hasn't been tested or is basically > blocked (cpu_cacheinfo->cpu_map_populated) from executing or there isn't > currently any benefit. Agreed. Thanks, Rafael