From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PROBLEM + PATCH] Sata port disabled by BIOS gets initialized by ata_piix drive Date: Sat, 09 Jun 2007 14:51:51 +0900 Message-ID: <466A3FF7.4090302@gmail.com> References: <9493.1181310368198.JavaMail.root@wombat.diezmil.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from wa-out-1112.google.com ([209.85.146.179]:2863 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752057AbXFIFxQ (ORCPT ); Sat, 9 Jun 2007 01:53:16 -0400 Received: by wa-out-1112.google.com with SMTP id v27so1332264wah for ; Fri, 08 Jun 2007 22:53:15 -0700 (PDT) In-Reply-To: <9493.1181310368198.JavaMail.root@wombat.diezmil.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: shyam_iyer@dell.com Cc: linux-ide@vger.kernel.org shyam_iyer@dell.com wrote: > Problem Sata disks are connected to onboard sata ports of PowerEdge > 1900 (ESB2 southbridge chipset). If one of the port is disabled in > the bios then they get enabled again by the ata_piix driver because > of a default port map being written to the Port control and status > register(0x91-93). Instead the driver should preserve the bios > setting by way of a fix like this. What happens if the port is enabled by the kernel? > Fix: The BIOS configured PCS value must be anded logically with the > default port map for the chipset. This way the BIOS information will > not be lost by the reinitialization of the config space by the > ata_piix driver. The below patch is against 2.6.21 kernel. I'm not sure whether this is a good idea and it has potential to break a lot of other configurations. That part of code is used for *all* ata_piix out there, so we need a really really good reason to change that. So, please explain what you're trying to fix better. -- tejun