ARM: relax ioremap prohibition (309caa9) for -final and -stable

... but produce a big warning about the problem as encouragement
for people to fix their drivers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index ab506272b2d..17e7b0b57e4 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -204,8 +204,12 @@ void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
         /*
          * Don't allow RAM to be mapped - this causes problems with ARMv6+
          */
-        if (WARN_ON(pfn_valid(pfn)))
-                return NULL;
+        if (pfn_valid(pfn)) {
+                printk(KERN_WARNING "BUG: Your driver calls ioremap() on system memory.  This leads\n"
+                       KERN_WARNING "to architecturally unpredictable behaviour on ARMv6+, and ioremap()\n"
+                       KERN_WARNING "will fail in the next kernel release.  Please fix your driver.\n");
+                WARN_ON(1);
+        }
 
         type = get_mem_type(mtype);
         if (!type)