[PATCH 4.9 85/86] earlycon: add reg-offset to physical address before mapping

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Greentime Hu <green.hu@xxxxxxxxx>

commit 1f66dd36bb18437397ea0d7882c52f7e3c476e15 upstream.

It will get the wrong virtual address because port->mapbase is not added
the correct reg-offset yet. We have to update it before earlycon_map()
is called

Signed-off-by: Greentime Hu <greentime@xxxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 088da2a17619 ("of: earlycon: Initialize port fields from DT properties")
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/tty/serial/earlycon.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -253,11 +253,12 @@ int __init of_setup_earlycon(const struc
 	}
 	port->mapbase = addr;
 	port->uartclk = BASE_BAUD * 16;
-	port->membase = earlycon_map(port->mapbase, SZ_4K);
 
 	val = of_get_flat_dt_prop(node, "reg-offset", NULL);
 	if (val)
 		port->mapbase += be32_to_cpu(*val);
+	port->membase = earlycon_map(port->mapbase, SZ_4K);
+
 	val = of_get_flat_dt_prop(node, "reg-shift", NULL);
 	if (val)
 		port->regshift = be32_to_cpu(*val);