[ARM] S3C: BUG_ON() if clock has already been registered

Add a simple check when registering a clock on whether
the clock has already been added to the list.

Any attempt to re-register a clock will cause the
clock list to be come looped and thus produces silent
failures when looking up clocks.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c/clock.c b/arch/arm/plat-s3c/clock.c
index 35249b58f383..da7ac07c7a0b 100644
--- a/arch/arm/plat-s3c/clock.c
+++ b/arch/arm/plat-s3c/clock.c
@@ -304,6 +304,9 @@ int s3c24xx_register_clock(struct clk *clk)
 
         /* add to the list of available clocks */
 
+        /* Quick check to see if this clock has already been registered. */
+        BUG_ON(clk->list.prev != clk->list.next);
+
         spin_lock(&clocks_lock);
         list_add(&clk->list, &clocks);
         spin_unlock(&clocks_lock);