OMAP clock/hwmod: fix off-by-one errors

Fix loop bailout off-by-one bugs reported by Juha Leppänen
<juha_motorsportcom@luukku.com>.

This second version incorporates comments from Russell King
<linux@arm.linux.org.uk>.  A new macro, 'omap_test_timeout', has
been created, with cleaner code, and existing code has been converted
to use it.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Juha Leppänen <juha_motorsportcom@luukku.com>
Cc: Russell King <linux@arm.linux.org.uk>

1 files changed, 20 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/include/plat/common.h b/arch/arm/plat-omap/include/plat/common.h
index 064f1730f43b..e9779676448b 100644
--- a/arch/arm/plat-omap/include/plat/common.h
+++ b/arch/arm/plat-omap/include/plat/common.h
@@ -71,4 +71,24 @@ void omap2_set_globals_sdrc(struct omap_globals *);
 void omap2_set_globals_control(struct omap_globals *);
 void omap2_set_globals_prcm(struct omap_globals *);
 
+/**
+ * omap_test_timeout - busy-loop, testing a condition
+ * @cond: condition to test until it evaluates to true
+ * @timeout: maximum number of microseconds in the timeout
+ * @index: loop index (integer)
+ *
+ * Loop waiting for @cond to become true or until at least @timeout
+ * microseconds have passed.  To use, define some integer @index in the
+ * calling code.  After running, if @index == @timeout, then the loop has
+ * timed out.
+ */
+#define omap_test_timeout(cond, timeout, index)                 \
+({                                                              \
+        for (index = 0; index < timeout; index++) {             \
+                if (cond)                                       \
+                        break;                                  \
+                udelay(1);                                      \
+        }                                                       \
+})
+
 #endif /* __ARCH_ARM_MACH_OMAP_COMMON_H */