diff --git a/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl-otto/mach-rtl-otto.h b/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl-otto/mach-rtl-otto.h
index aa917c2ef7..f85dee6591 100644
--- a/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl-otto/mach-rtl-otto.h
+++ b/target/linux/realtek/files-6.12/arch/mips/include/asm/mach-rtl-otto/mach-rtl-otto.h
@@ -28,6 +28,7 @@
 
 #define RTL838X_INT_RW_CTRL		(0x0058)
 #define RTL838X_EXT_VERSION		(0x00D0)
+#define RTL838X_PLL_CML_CTRL		(0x0ff8)
 
 #define RTL931X_LED_GLB_CTRL		(0x0600)
 #define RTL931X_MAC_L2_GLOBAL_CTRL2	(0x1358)
diff --git a/target/linux/realtek/files-6.12/arch/mips/rtl-otto/prom.c b/target/linux/realtek/files-6.12/arch/mips/rtl-otto/prom.c
index b0975c51ae..2ec2b3f0dd 100644
--- a/target/linux/realtek/files-6.12/arch/mips/rtl-otto/prom.c
+++ b/target/linux/realtek/files-6.12/arch/mips/rtl-otto/prom.c
@@ -101,9 +101,21 @@ static int rtlsmp_register(void)
 
 static void __init apply_early_quirks(void)
 {
-	/* Open up write protected registers. Never mess with this elsewhere */
-	if (soc_info.family == RTL8380_FAMILY_ID)
+	if (soc_info.family == RTL8380_FAMILY_ID) {
+		/*
+		 * Open up write protected registers. SDK opens/closes this whenever needed. For
+		 * simplicity always work with an "open" register set.
+		 */
 		sw_w32(0x3, RTL838X_INT_RW_CTRL);
+		/*
+		 * Disable 4 byte address mode of flash controller. If this bit is not cleared
+		 * the watchdog cannot reset the SoC. The SDK changes this short before restart.
+		 * Until this quirk was implemented all RTL838x devices ran with this disabled
+		 * because of a coding error. As no issues were detected keep the behaviour
+		 * until more details are known.
+		 */
+		sw_w32_mask(BIT(30), 0, RTL838X_PLL_CML_CTRL);
+	}
 }
 
 static void __init apply_dts_quirks(void)