From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] amd74xx: don't configure udma mode higher than BIOS did Date: Mon, 05 Feb 2007 21:33:03 +0900 Message-ID: <45C723FF.2060405@gmail.com> References: <20070205075836.GG1625@htj.dyndns.org> <20070205112410.5a3c3182@localhost.localdomain> <45C72012.7050605@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.232]:10694 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932240AbXBEMdJ (ORCPT ); Mon, 5 Feb 2007 07:33:09 -0500 Received: by nz-out-0506.google.com with SMTP id s1so1590328nze for ; Mon, 05 Feb 2007 04:33:08 -0800 (PST) In-Reply-To: <45C72012.7050605@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cc: bzolnier@gmail.com, linux-ide@vger.kernel.org Forgot to reply about some stuff. Adding. Tejun Heo wrote: > Alan wrote: >>> This patch makes amd74xx not configure udma mode higher than BIOS did. >>> If BIOS configured the device <= udma44, udma33 is the maximum speed. >> NAK >> >> The boot firmware for AMD/Nvidia chips is only run on PC, and the data is >> only valid on some of them, in some cases, and not after a suspend/resume >> cycle. To prevent that, the value is cached on driver probe and written back on driver detach on pata_amd, which is necessary even when there is no suspend/resume as mode programming alters the content of the register. amd74xx cannot be unloaded, so caching is enough. Also, doesn't suspend/resume cycle store and restore PCI space anyway? Thanks. -- tejun