From mboxrd@z Thu Jan 1 00:00:00 1970 From: Toshi Kani Subject: Re: [PATCH] ACPI / init: Switch over platform to the ACPI mode later Date: Wed, 03 Jun 2015 11:13:57 -0600 Message-ID: <1433351637.23540.170.camel@misato.fc.hp.com> References: <12578608.kKCTgirQ6f@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from g9t5009.houston.hp.com ([15.240.92.67]:55005 "EHLO g9t5009.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753432AbbFCRde (ORCPT ); Wed, 3 Jun 2015 13:33:34 -0400 In-Reply-To: <12578608.kKCTgirQ6f@vostro.rjw.lan> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: ACPI Devel Maling List , Linux Kernel Mailing List , Len Brown , Marius Tolzmann , Matt Fleming , Chun-Yi , Aaron Lu , Lv Zheng 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().) Otherwise, the change looks good. Acked-by: Toshi Kani Thanks, -Toshi