From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755052Ab0IYCIC (ORCPT ); Fri, 24 Sep 2010 22:08:02 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:55554 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499Ab0IYCIA (ORCPT ); Fri, 24 Sep 2010 22:08:00 -0400 X-Sasl-enc: QCf2nadV/vTvrw05adsJHcyJKAoddmmXCfGjcXhFvUeN 1285380479 Date: Fri, 24 Sep 2010 23:07:53 -0300 From: Henrique de Moraes Holschuh To: Vernon Mauery Cc: Randy Dunlap , Arnd Bergmann , Linux Kernel Mailing List , Keith Mannthey Subject: Re: [RFC][Patch] IBM Real-Time "SMI Free" mode driver -v5 Message-ID: <20100925020753.GA31997@khazad-dum.debian.net> References: <20100921224610.GO13162@lucy> <20100923221253.GA4960@lucy> <20100923225346.GB4960@lucy> <201009241512.39311.arnd@arndb.de> <20100924095625.5beedf5a.rdunlap@xenotime.net> <20100924210642.GE10777@lucy> <20100924142006.a79833ab.rdunlap@xenotime.net> <20100924213009.GF10777@lucy> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100924213009.GF10777@lucy> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 24 Sep 2010, Vernon Mauery wrote: > >>+/* The RTL table as presented by the EBDA: */ > >>+struct ibm_rtl_table { > >>+ char signature[5]; > > > >Question: are all 5 bytes of signature[] used? It looks like the search code > >only checks for 32 bits of signature (and the last byte can be garbage?). > > Technically, the 5 bytes are supposed to be "_RTL_", but it is a lot > easier to just check _RTL since we can do that with a single read. > I suppose I could do a 64-bit read and mask the bits that matter. Well, as long as you guys write in stone there at IBM that you will remember to not have a possible future _RTL2_ that would clash horribly with an non-up-to-date version of the driver that has no clue about RTL2 and still would match the signature because it only looks at the first 32 bits... -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh