diff --git a/arch/mips/ath79/setup.c b/arch/mips/ath79/setup.c
index d5b3c9057018..a0233a2c1988 100644
--- a/arch/mips/ath79/setup.c
+++ b/arch/mips/ath79/setup.c
@@ -51,20 +51,6 @@ static void ath79_halt(void)
 		cpu_wait();
 }
 
-static void __init ath79_detect_mem_size(void)
-{
-	unsigned long size;
-
-	for (size = ATH79_MEM_SIZE_MIN; size < ATH79_MEM_SIZE_MAX;
-	     size <<= 1) {
-		if (!memcmp(ath79_detect_mem_size,
-			    ath79_detect_mem_size + size, 1024))
-			break;
-	}
-
-	add_memory_region(0, size, BOOT_MEM_RAM);
-}
-
 static void __init ath79_detect_sys_type(void)
 {
 	char *chip = "????";
@@ -212,7 +198,7 @@ void __init plat_mem_setup(void)
 					 AR71XX_DDR_CTRL_SIZE);
 
 	ath79_detect_sys_type();
-	ath79_detect_mem_size();
+	detect_memory_region(0, ATH79_MEM_SIZE_MIN, ATH79_MEM_SIZE_MAX);
 	ath79_clocks_init();
 
 	_machine_restart = ath79_restart;