Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964927AbXHZB4O (ORCPT ); Sat, 25 Aug 2007 21:56:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964812AbXHZBz7 (ORCPT ); Sat, 25 Aug 2007 21:55:59 -0400 Received: from palinux.external.hp.com ([192.25.206.14]:55903 "EHLO mail.parisc-linux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964813AbXHZBz6 (ORCPT ); Sat, 25 Aug 2007 21:55:58 -0400 Date: Sat, 25 Aug 2007 19:55:56 -0600 From: Matthew Wilcox To: linux-pci@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org Cc: Robert Hancock , Jesse Barnes , Greg KH Subject: [PATCH] Fix boot-time hang on G31/G33 PC Message-ID: <20070826015556.GC14130@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2186 Lines: 61 This patch, loosely based on a patch from Robert Hancock, which was in turn based on a patch from Jesse Barnes, fixes a boot-time hang on my shiny new PC. The 'conflict' mentioned in the patch in my case happens to be between mmconfig and the graphics card, but it could easily be between any pair of devices if they are left enabled by the BIOS and mappen in the wrong place. Signed-off-by: Matthew Wilcox diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 34b8dae..51ef450 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -180,11 +180,26 @@ static inline int is_64bit_memory(u32 mask) return 0; } +/* + * Sizing PCI BARs requires us to disable decoding, otherwise we may run + * into conflicts with other devices while trying to size the BAR. Normally + * this isn't a problem, but it happens on some machines normally, and can + * happen on others during PCI device hotplug. Don't disable BARs for host + * bridges, though. Some of them do silly things like disable accesses to + * RAM from the CPU + */ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) { unsigned int pos, reg, next; u32 l, sz; struct resource *res; + u16 orig_cmd; + + if ((dev->class >> 8) != PCI_CLASS_BRIDGE_HOST) { + pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); + pci_write_config_word(dev, PCI_COMMAND, + orig_cmd & ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO)); + } for(pos=0; posclass >> 8) != PCI_CLASS_BRIDGE_HOST) + pci_write_config_word(dev, PCI_COMMAND, orig_cmd); } void __devinit pci_read_bridge_bases(struct pci_bus *child) -- "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/