[patch 18/43] resources: skip sanity check of busy resources

Greg KH
2009-01-31T03:05:32Z

[-- Attachment #1: resources-skip-sanity-check-of-busy-resources.patch --]
[-- Type: text/plain, Size: 1692 bytes --]

2.6.28-stable review patch. If anyone has any objections, please let us know.

------------------

From: Arjan van de Ven <arjan@linux.intel.com>

commit 3ac52669c7a24b93663acfcab606d1065ed1accd upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
kernel/resource.c | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -853,6 +853,15 @@ int iomem_map_sanity_check(resource_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,