[PATCH 4.9 19/25] serial: 8250_fintek: Fix finding base_port with activated SuperIO

Greg Kroah-Hartman
2017-11-22T10:14:38Z

From: Ji-Ze Hong (Peter Hong) <hpeter@gmail.com>

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@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>

---
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;