From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Starikovskiy Subject: Re: ISA -> ISA_ (Re: [GIT PATCH] ACPI patches for 2.6.25-rc6) Date: Wed, 26 Mar 2008 22:21:42 +0300 Message-ID: <47EAA246.3050707@gmail.com> References: <200803180510.47670.lenb@kernel.org> <200803260956.55804.bjorn.helgaas@hp.com> <47EA86D9.7040404@gmail.com> <200803261247.31531.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from fk-out-0910.google.com ([209.85.128.191]:23824 "EHLO fk-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753556AbYCZTVu (ORCPT ); Wed, 26 Mar 2008 15:21:50 -0400 Received: by fk-out-0910.google.com with SMTP id 19so4894237fkr.5 for ; Wed, 26 Mar 2008 12:21:47 -0700 (PDT) In-Reply-To: <200803261247.31531.bjorn.helgaas@hp.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Bjorn Helgaas Cc: Len Brown , Ingo Molnar , Corentin CHARY , Linus Torvalds , Andrew Morton , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org Bjorn Helgaas wrote: > On Wednesday 26 March 2008 11:24:41 am Alexey Starikovskiy wrote: > >> Bjorn Helgaas wrote: >> >>> I'm curious about how this works. I disassembled the DSDT from >>> http://bugzilla.kernel.org/show_bug.cgi?id=4773 (I attached the disassembly >>> at http://bugzilla.kernel.org/attachment.cgi?id=15448&action=view), and >>> the _PRT contains "_SB" and "ISA" (no trailing underscores): >>> >>> Package (0x04) >>> { >>> 0x000DFFFF, >>> 0x00, >>> \_SB.PCI0.ISA.LNKA, >>> 0x00 >>> } >>> >>> But by the time we get to acpi_pci_irq_add_entry(), we've added the >>> underscores somewhere (see >>> http://bugzilla.kernel.org/attachment.cgi?id=15423&action=view): >>> >>> 0000:00:0d[A] -> \_SB_.PCI0.ISA_.LNKA >>> >>> I don't know where this happens, but it certainly confused me, and >>> it seems like it could lead to other bugs. >>> >>> >> ACPI is supposed to add trailing underscore for pad all names to 4 bytes. >> So ISA will be padded to ISA_. >> > > The questions are "where does this happen?" and "why does it not > apply to other things like asus_acpi.c?" > 1. drivers/acpi/namespace/nsutils.c:419