Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756344AbZA0QEv (ORCPT ); Tue, 27 Jan 2009 11:04:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755894AbZA0QEX (ORCPT ); Tue, 27 Jan 2009 11:04:23 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:51580 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755857AbZA0QEW (ORCPT ); Tue, 27 Jan 2009 11:04:22 -0500 Date: Tue, 27 Jan 2009 11:04:21 -0500 From: Kyle McMartin To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, arjan@linux.intel.com Subject: [PATCH stable] resources: skip sanity check of busy resources Message-ID: <20090127160421.GF5034@bombadil.infradead.org> Reply-To: kyle@infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2057 Lines: 55 From: Arjan van de Ven Impact: reduce false positives in iomem_map_sanity_check() Some drivers (vesafb) only map/reserve a portion of a resource. If then some other driver comes in and maps the whole resource, the current code WARN_ON's. This is not the intent of the checks in iomem_map_sanity_check(); rather these checks want to warn when crossing *hardware* resources only. This patch skips BUSY resources as suggested by Linus. Note: having two drivers talk to the same hardware at the same time is obviously not optimal behavior, but that's a separate story. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Kyle McMartin --- Bug fix for 2.6.28-stable only (relevant iomem_map_sanity_check hadn't been added to 2.6.27.) This resolves a fairly nasty boot time WARN in acpi ec seen on a number of systems. (RH #480700) kernel/resource.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 4337063..e633106 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -853,6 +853,15 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) continue; + /* + * if a resource is "BUSY", it's not a hardware resource + * but a driver mapping of such a resource; we don't want + * to warn for those; some drivers legitimately map only + * partial hardware resources. (example: vesafb) + */ + if (p->flags & IORESOURCE_BUSY) + continue; + printk(KERN_WARNING "resource map sanity check conflict: " "0x%llx 0x%llx 0x%llx 0x%llx %s\n", (unsigned long long)addr, -- 1.6.0.6 -- 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/