From fd97e66c5529046e989a0879c3bb58fddb592c71 Mon Sep 17 00:00:00 2001
From: "Ji-Ze Hong (Peter Hong)" <hpeter@gmail.com>
Date: Tue, 17 Oct 2017 14:23:08 +0800
Subject: [PATCH] serial: 8250_fintek: Fix finding base_port with activated SuperIO
Git-commit: fd97e66c5529046e989a0879c3bb58fddb592c71
Patch-mainline: v4.15-rc1
References: bsc#1051510

The SuperIO will be configured at boot time by BIOS, but some BIOS
will not deactivate the SuperIO when the end of configuration. It'll
lead to mismatch for pdata->base_port in probe_setup_port(). So we'll
deactivate all SuperIO before activate special base_port in
fintek_8250_enter_key().

Tested on iBASE MI802.

Cc: stable@vger.kernel.org
Tested-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Reviewd-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/tty/serial/8250/8250_fintek.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -118,6 +118,9 @@ static int fintek_8250_enter_key(u16 bas
 	if (!request_muxed_region(base_port, 2, "8250_fintek"))
 		return -EBUSY;
 
+	/* Force to deactive all SuperIO in this base_port */
+	outb(EXIT_KEY, base_port + ADDR_PORT);
+
 	outb(key, base_port + ADDR_PORT);
 	outb(key, base_port + ADDR_PORT);
 	return 0;