diff --git a/arch/arm/mach-s3c64xx/clock.c b/arch/arm/mach-s3c64xx/clock.c
index 8cf39e33579e3bb9c7d30eceb6afcaa5914e6d2c..872e68361eb44d8f289c963e0cf0456d01dc7822 100644
--- a/arch/arm/mach-s3c64xx/clock.c
+++ b/arch/arm/mach-s3c64xx/clock.c
@@ -744,7 +744,13 @@ void __init_or_cpufreq s3c6400_setup_clocks(void)
 	printk(KERN_INFO "S3C64XX: PLL settings, A=%ld, M=%ld, E=%ld\n",
 	       apll, mpll, epll);
 
-	hclk2 = mpll / GET_DIV(clkdiv0, S3C6400_CLKDIV0_HCLK2);
+	if(__raw_readl(S3C64XX_OTHERS) & S3C64XX_OTHERS_SYNCMUXSEL)
+		/* Synchronous mode */
+		hclk2 = apll / GET_DIV(clkdiv0, S3C6400_CLKDIV0_HCLK2);
+	else
+		/* Asynchronous mode */
+		hclk2 = mpll / GET_DIV(clkdiv0, S3C6400_CLKDIV0_HCLK2);
+
 	hclk = hclk2 / GET_DIV(clkdiv0, S3C6400_CLKDIV0_HCLK);
 	pclk = hclk2 / GET_DIV(clkdiv0, S3C6400_CLKDIV0_PCLK);
 
diff --git a/arch/arm/mach-s3c64xx/include/mach/regs-sys.h b/arch/arm/mach-s3c64xx/include/mach/regs-sys.h
index 774e0de31400506148a460a58dda99fc63de8a69..b91e02093289d6af7c9a216adaa1273acf8f5f4b 100644
--- a/arch/arm/mach-s3c64xx/include/mach/regs-sys.h
+++ b/arch/arm/mach-s3c64xx/include/mach/regs-sys.h
@@ -26,5 +26,6 @@
 #define S3C64XX_OTHERS		S3C_SYSREG(0x900)
 
 #define S3C64XX_OTHERS_USBMASK	(1 << 16)
+#define S3C64XX_OTHERS_SYNCMUXSEL	(1 << 6)
 
 #endif /* _PLAT_REGS_SYS_H */