From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750768AbWECTug (ORCPT ); Wed, 3 May 2006 15:50:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750773AbWECTug (ORCPT ); Wed, 3 May 2006 15:50:36 -0400 Received: from fmr19.intel.com ([134.134.136.18]:60136 "EHLO orsfmr004.jf.intel.com") by vger.kernel.org with ESMTP id S1750768AbWECTuf (ORCPT ); Wed, 3 May 2006 15:50:35 -0400 Date: Wed, 3 May 2006 12:58:48 -0700 From: mark gross To: akpm@osdl.org Cc: linux-kernel@vger.kernel.org, bluesmoke-devel@lists.sourceforge.net, mark.gross@intel.com Subject: [PATCH] EDAC Coexistance with BIOS Message-ID: <20060503195848.GA13018@linux.intel.com> Reply-To: mgross@linux.intel.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The following patch addresses the issue of EDAC/BIOS coexistence for the e752x chip-sets. It is a patch agaist 2.6.17-rc3-mm1. We have found a problem where the BIOS will start the system with the error registers (dev0:fun1) hidden and assuming it has exclusive access to them. The edac driver violates this assumption. The work around this patch offers is to honor the hidden-ness as an indication that it is not safe to use those registers. Please apply Signed-off-by: Mark Gross Thanks, diff -urN -X linux-2.6.17-rc3-mm1/Documentation/dontdiff linux-2.6.17-rc3-mm1/drivers/edac/e752x_edac.c linux-2.6.17-rc3-mm1_edac/drivers/edac/e752x_edac.c --- linux-2.6.17-rc3-mm1/drivers/edac/e752x_edac.c 2006-05-03 11:31:04.000000000 -0700 +++ linux-2.6.17-rc3-mm1_edac/drivers/edac/e752x_edac.c 2006-05-03 11:20:54.000000000 -0700 @@ -25,6 +25,8 @@ #include #include "edac_mc.h" +static int force_function_unhide; + #define e752x_printk(level, fmt, arg...) \ edac_printk(level, "e752x", fmt, ##arg) @@ -782,8 +784,16 @@ debugf0("%s(): mci\n", __func__); debugf0("Starting Probe1\n"); - /* enable device 0 function 1 */ + /* check to see if device 0 function 1 is enabled; if it isn't, we + * assume the BIOS has reserved it for a reason and is expecting + * exclusive access, we take care not to violate that assumption and + * fail the probe. */ pci_read_config_byte(pdev, E752X_DEVPRES1, &stat8); + if (!force_function_unhide && !(stat8 & (1 << 5))) { + printk(KERN_INFO "Contact your BIOS vendor to see if the " + "E752x error registers can be safely un-hidden\n"); + goto fail; + } stat8 |= (1 << 5); pci_write_config_byte(pdev, E752X_DEVPRES1, stat8); @@ -1063,3 +1073,8 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Linux Networx (http://lnxi.com) Tom Zimmerman\n"); MODULE_DESCRIPTION("MC support for Intel e752x memory controllers"); + +module_param(force_function_unhide, int, 0444); +MODULE_PARM_DESC(force_function_unhide, "if BIOS sets Dev0:Fun1 up as hidden:" +" 1=force unhide and hope BIOS doesn't fight driver for Dev0:Fun1 access"); +