From 0cfe11635803a65c7f80ed2d6ea909329d1f9e6f Mon Sep 17 00:00:00 2001 From: Lubomir Rintel <lkundrak@v3.sk> Date: Sun, 24 Feb 2019 13:00:53 +0100 Subject: [PATCH] serial: 8250_of: assume reg-shift of 2 for mrvl,mmp-uart commit f4817843e39ce78aace0195a57d4e8500a65a898 upstream. There are two other drivers that bind to mrvl,mmp-uart and both of them assume register shift of 2 bits. There are device trees that lack the property and rely on that assumption. If this driver wins the race to bind to those devices, it should behave the same as the older deprecated driver. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/tty/serial/8250/8250_of.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c index 7a8b5fc81a19..f89dfde934a3 100644 --- a/drivers/tty/serial/8250/8250_of.c +++ b/drivers/tty/serial/8250/8250_of.c @@ -97,6 +97,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev, if (of_property_read_u32(np, "reg-offset", &prop) == 0) port->mapbase += prop; + /* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */ + if (of_device_is_compatible(np, "mrvl,mmp-uart")) + port->regshift = 2; + /* Check for registers offset within the devices address range */ if (of_property_read_u32(np, "reg-shift", &prop) == 0) port->regshift = prop;