Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932911AbbFJCG4 (ORCPT ); Tue, 9 Jun 2015 22:06:56 -0400 Received: from mail-pa0-f50.google.com ([209.85.220.50]:33289 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752557AbbFJCGs (ORCPT ); Tue, 9 Jun 2015 22:06:48 -0400 Message-ID: <55779BB0.6030900@linaro.org> Date: Wed, 10 Jun 2015 10:06:40 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: "Rafael J. Wysocki" , Toshi Kani CC: ACPI Devel Maling List , Linux Kernel Mailing List , Len Brown , Marius Tolzmann , Matt Fleming , Chun-Yi , Aaron Lu , Lv Zheng Subject: Re: [PATCH] ACPI / init: Switch over platform to the ACPI mode later References: <12578608.kKCTgirQ6f@vostro.rjw.lan> <1433351637.23540.170.camel@misato.fc.hp.com> <13170654.9h99FfQLut@vostro.rjw.lan> In-Reply-To: <13170654.9h99FfQLut@vostro.rjw.lan> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4552 Lines: 103 On 06/10/2015 07:48 AM, Rafael J. Wysocki wrote: > On Wednesday, June 03, 2015 11:13:57 AM Toshi Kani wrote: >> On Sat, 2015-05-30 at 14:21 +0200, Rafael J. Wysocki wrote: >>> From: Rafael J. Wysocki >>> >>> Commit 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before >>> timekeeping_init()" moved the ACPI subsystem initialization, >>> including the ACPI mode enabling, to an earlier point in the >>> initialization sequence, to allow the timekeeping subsystem >>> use ACPI early. Unfortunately, that resulted in boot regressions >>> on some systems and the early ACPI initialization was moved toward >>> its original position in the kernel initialization code by commit >>> c4e1acbb35e4 "ACPI / init: Invoke early ACPI initialization later". >>> >>> However, that turns out to be insufficient, as boot is still broken >>> on the Tyan S8812 mainboard. >>> >>> To fix that issue, split the ACPI early initialization code into >>> two pieces so the majority of it still located in acpi_early_init() >>> and the part switching over the platform into the ACPI mode goes into >>> a new function, acpi_subsystem_init(), executed at the original early >>> ACPI initialization spot. >>> >>> That fixes the Tyan S8812 boot problem, but still allows ACPI >>> tables to be loaded earlier which is useful to the EFI code in >>> efi_enter_virtual_mode(). >>> >>> Link: https://bugzilla.kernel.org/show_bug.cgi?id=97141 >>> Reported-and-tested-by: Marius Tolzmann >>> Signed-off-by: Rafael J. Wysocki >> >> Can you add comments to acpi_early_init() and acpi_subsystem_init() to >> clarify what ACPI features are enabled at each phase, and what >> dependency they have in the boot sequence? (The same goes to >> early_acpi_boot_init() and acpi_boot_init().) > > OK, update follows. > > --- > From: Rafael J. Wysocki > Subject: ACPI / init: Switch over platform to the ACPI mode later > > Commit 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before > timekeeping_init()" moved the ACPI subsystem initialization, > including the ACPI mode enabling, to an earlier point in the > initialization sequence, to allow the timekeeping subsystem > use ACPI early. Unfortunately, that resulted in boot regressions > on some systems and the early ACPI initialization was moved toward > its original position in the kernel initialization code by commit > c4e1acbb35e4 "ACPI / init: Invoke early ACPI initialization later". > > However, that turns out to be insufficient, as boot is still broken > on the Tyan S8812 mainboard. > > To fix that issue, split the ACPI early initialization code into > two pieces so the majority of it still located in acpi_early_init() > and the part switching over the platform into the ACPI mode goes into > a new function, acpi_subsystem_init(), executed at the original early > ACPI initialization spot. > > That fixes the Tyan S8812 boot problem, but still allows ACPI > tables to be loaded earlier which is useful to the EFI code in > efi_enter_virtual_mode(). > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=97141 > Fixes: 73f7d1ca3263 "ACPI / init: Run acpi_early_init() before timekeeping_init()" > Reported-and-tested-by: Marius Tolzmann > Signed-off-by: Rafael J. Wysocki > Acked-by: Toshi Kani > --- > drivers/acpi/bus.c | 56 +++++++++++++++++++++++++++++++++++++-------------- > include/linux/acpi.h | 2 + > init/main.c | 1 > 3 files changed, 44 insertions(+), 15 deletions(-) > > Index: linux-pm/drivers/acpi/bus.c > =================================================================== > --- linux-pm.orig/drivers/acpi/bus.c > +++ linux-pm/drivers/acpi/bus.c > @@ -470,6 +470,16 @@ static int __init acpi_bus_init_irq(void > return 0; > } > > +/** > + * acpi_early_init - Initialize ACPICA and populate the ACPI namespace. > + * > + * The ACPI tables are accessible after this, but the handling of events has not Maybe we need to explicitly say that it's DSDT/SSDT, because static tables such as FADT and MADT are accessible in the very early stage of boot (in setup_arch()). Other than that, Reviewed-by: Hanjun Guo Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/