From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750812AbWDPWmQ (ORCPT ); Sun, 16 Apr 2006 18:42:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750813AbWDPWmQ (ORCPT ); Sun, 16 Apr 2006 18:42:16 -0400 Received: from mx1.redhat.com ([66.187.233.31]:29834 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1750812AbWDPWmQ (ORCPT ); Sun, 16 Apr 2006 18:42:16 -0400 Date: Sun, 16 Apr 2006 17:42:15 -0500 From: Dave Jones To: Linux Kernel Subject: Improve PCI config space writeback. Message-ID: <20060416224215.GA732@redhat.com> Mail-Followup-To: Dave Jones , Linux Kernel Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org At least one laptop blew up on resume from suspend with a black screen due to a lack of this patch. By only writing back config space that is different, we minimise the possibility of accidents like this. Signed-off-by: Dave Jones --- linux-2.6.16.noarch/drivers/pci/pci.c~ 2006-04-16 17:36:34.000000000 -0500 +++ linux-2.6.16.noarch/drivers/pci/pci.c 2006-04-16 17:37:42.000000000 -0500 @@ -461,9 +461,17 @@ int pci_restore_state(struct pci_dev *dev) { int i; + int val; - for (i = 0; i < 16; i++) - pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]); + for (i = 0; i < 16; i++) { + pci_read_config_dword(dev, i * 4, &val); + if (val != dev->saved_config_space[i]) { + printk (KERN_DEBUG "PM: Writing back config space on device %s at offset %x. (Was %x, writing %x)\n", + pci_name(dev), i, + val, (int) dev->saved_config_space[i]); + pci_write_config_dword(dev,i * 4, dev->saved_config_space[i]); + } + } pci_restore_msi_state(dev); pci_restore_msix_state(dev); return 0;