ARM: mach-ux500: add explicit cpu_relax() for busy wait loop

using cpu_relax in busy loops is a well-known idiom in the kernel. It's more
for documentation purposes than technically needed here.

Cc: Jamie Iles <jamie@jamieiles.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/arch/arm/mach-ux500/cpu.c b/arch/arm/mach-ux500/cpu.c
index 1da23bb87c16bcec2047d9ac8e08e474d2f505ce..76ee3557ae3d9dcfe912e9ae644895c30fade821 100644 (file)
--- a/arch/arm/mach-ux500/cpu.c
+++ b/arch/arm/mach-ux500/cpu.c
@@ -62,7 +62,7 @@ static inline void ux500_cache_wait(void __iomem *reg, unsigned long mask)
 {
        /* wait for the operation to complete */
        while (readl_relaxed(reg) & mask)
-               ;
+               cpu_relax();
 }
 
 static inline void ux500_cache_sync(void)