This is a note to let you know that I've just added the patch titled serial: 8250_fintek: Fix finding base_port with activated SuperIO to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-8250_fintek-fix-finding-base_port-with-activated-superio.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From fd97e66c5529046e989a0879c3bb58fddb592c71 Mon Sep 17 00:00:00 2001 From: "Ji-Ze Hong (Peter Hong)" <hpeter@xxxxxxxxx> Date: Tue, 17 Oct 2017 14:23:08 +0800 Subject: serial: 8250_fintek: Fix finding base_port with activated SuperIO From: Ji-Ze Hong (Peter Hong) <hpeter@xxxxxxxxx> commit fd97e66c5529046e989a0879c3bb58fddb592c71 upstream. 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. Tested-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx> Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx> Reviewd-by: Alan Cox <alan@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -54,6 +54,9 @@ 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; Patches currently in stable-queue which might be from hpeter@xxxxxxxxx are queue-4.9/serial-8250_fintek-fix-finding-base_port-with-activated-superio.patch