From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Renninger Subject: Re: [PATH 1/5 -v2] acpi, IO memory pre-mapping and atomic accessing Date: Fri, 18 Dec 2009 14:42:38 +0100 Message-ID: <4B2B86CE.4020304@suse.de> References: <1260429413.15264.393.camel@yhuang-dev.sh.intel.com> <200912111036.15063.bjorn.helgaas@hp.com> <1260839053.12561.1098.camel@yhuang-dev.sh.intel.com> <200912151047.14196.bjorn.helgaas@hp.com> <1260926595.12561.1188.camel@yhuang-dev.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from cantor2.suse.de ([195.135.220.15]:55575 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751225AbZLRNnr (ORCPT ); Fri, 18 Dec 2009 08:43:47 -0500 In-Reply-To: <1260926595.12561.1188.camel@yhuang-dev.sh.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Huang Ying Cc: Bjorn Helgaas , "lenb@kernel.org" , ACPI Devel Maling List , Andi Kleen , "linux-kernel@vger.kernel.org" On 12/16/2009 02:23 AM, Huang Ying wrote: > On Wed, 2009-12-16 at 01:47 +0800, Bjorn Helgaas wrote: >> On Monday 14 December 2009 06:04:13 pm Huang Ying wrote: ... >>> The checking here is for bug in firmware not software. I think it is >>> necessary for the user to know where the bugs may come from, and it is >>> hard to express the bug in return code. >> >> Yes, I understand that this is checking for firmware bugs. My point >> is that when a user sees this in his dmesg log: >> >> Invalid bit width in GAR, firmware bug? >> >> we have no context, and even a kernel developer can't figure out what >> to do. We could ask for a copy of the FADT and DSDT, but even then, >> we don't know *which* GAR structure to look at, so we'll probably have >> to add some instrumentation and ask the user to reproduce the problem. >> >> If the check were in the caller, it could at least say something like: >> >> ACPI: couldn't map generic address [io 0xcf8] for PCI config access >> >> which would give us more useful information. > > En... Yes, some information about the invalid GAR is helpful. But the > GAR information is available in acpi_check_gar too, so we can output > something as follow in acpi_check_gar: > > Invalid bit width in GAR [mem 0x8029ff8 24], firmware bug? > > Your message looks like a software issue instead of firmware bug. This > may confuse the user and developer. Please use one of these (cmp. with include/linux/kernel.h when to use which): #define FW_BUG "[Firmware Bug]: " #define FW_WARN "[Firmware Warn]: " #define FW_INFO "[Firmware Info]: " It's great that someone cares to tell syslog/users that it's a firmware bug, that should get more common... Thomas