Messages in this thread Patch in this message | | | Date | Tue, 27 Jan 2009 11:04:21 -0500 | From | Kyle McMartin <> | Subject | [PATCH stable] resources: skip sanity check of busy resources |
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From: Arjan van de Ven <arjan@linux.intel.com>
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 <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Kyle McMartin <kyle@redhat.com> ---
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
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