From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754360AbcIJOhj (ORCPT ); Sat, 10 Sep 2016 10:37:39 -0400 Received: from mail.skyhub.de ([78.46.96.112]:33563 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753252AbcIJOhh (ORCPT ); Sat, 10 Sep 2016 10:37:37 -0400 Date: Sat, 10 Sep 2016 16:30:31 +0200 From: Borislav Petkov To: Rui Wang Cc: bhelgaas@google.com, torvalds@linux-foundation.org, peterz@infradead.org, tglx@linutronix.de, helgaas@kernel.org, linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, rjw@rjwysocki.net, tony.luck@intel.com, mingo@kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: 584c5c422f6c ("x86/ioapic: Support hot-removal of IOAPICs present during boot") Message-ID: <20160910143031.5s4psayo4wqrmpt2@pd.tnic> References: <20160910112744.4a6inn5bnjxsseak@pd.tnic> <1473513090-30218-1-git-send-email-rui.y.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1473513090-30218-1-git-send-email-rui.y.wang@intel.com> User-Agent: NeoMutt/ (1.7.0) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 10, 2016 at 09:11:30PM +0800, Rui Wang wrote: > Thanks for the analysis. Looks like acpi_gbl_root_node == 0. It is Is ACPI_HANDLE(root_bus->bridge) == ACPI_ROOT_OBJECT? Because this is what the code does but I can't see it from the code that the handle is of type ACPI_ROOT_OBJECT... > initialized earlier than where we call acpi_ioapic_add(). > start_kernel() > ->acpi_early_init() > ->acpi_initialize_subsystem() > ->acpi_ns_root_initialize() > -> acpi_gbl_root_node = ... > > > But acpi_gbl_root_node can be 0 if acpi_disabled == 1. > Do you somehow have acpi turned off (!CONFIG_ACPI or booting with acpi=off)? Nope. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.