rtl8xxxu: If fw running in RAM, reset the 8051 before trying to download a new one

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c

@@ -2089,7 +2089,7 @@ static int rtl8xxxu_start_firmware(struct rtl8xxxu_priv *priv)
 static int rtl8xxxu_download_firmware(struct rtl8xxxu_priv *priv)
 {
 	int pages, remainder, i, ret;
-	u8 val8;
+	u8 val8, sys_func;
 	u16 val16;
 	u32 val32;
 	u8 *fwptr;
@@ -2103,6 +2103,23 @@ static int rtl8xxxu_download_firmware(struct rtl8xxxu_priv *priv)
 	val16 |= SYS_FUNC_CPU_ENABLE;
 	rtl8xxxu_write16(priv, REG_SYS_FUNC, val16);
 
+	val8 = rtl8xxxu_read8(priv, REG_MCU_FW_DL);
+	if (val8 & MCU_FW_RAM_SEL) {
+		pr_info("do the RAM reset\n");
+		rtl8xxxu_write8(priv, REG_MCU_FW_DL, 0x00);
+		val8 = rtl8xxxu_read8(priv, REG_RSV_CTRL + 1);
+		val8 &= ~BIT(3);
+		rtl8xxxu_write8(priv, REG_RSV_CTRL + 1, val8);
+		sys_func = rtl8xxxu_read8(priv, REG_SYS_FUNC + 1);
+		sys_func &= ~BIT(2);
+		rtl8xxxu_write8(priv, REG_SYS_FUNC + 1, sys_func);
+		val8 = rtl8xxxu_read8(priv, REG_RSV_CTRL + 1);
+		val8 |= BIT(3);
+		rtl8xxxu_write8(priv, REG_RSV_CTRL + 1, val8);
+		sys_func |= BIT(2);
+		rtl8xxxu_write8(priv, REG_SYS_FUNC + 1, sys_func);
+	}
+
 	/* MCU firmware download enable */
 	val8 = rtl8xxxu_read8(priv, REG_MCU_FW_DL);
 	val8 |= MCU_FW_DL_ENABLE;