40963de8762b72a1bdd19d9ec5c4541289a8d1a8
[openwrt/openwrt.git] / target / linux / brcm2708 / patches-4.9 / 950-0087-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch
1 From b34475b447c7e97fa9c4a854849f6e856fe59931 Mon Sep 17 00:00:00 2001
2 From: Phil Elwell <phil@raspberrypi.org>
3 Date: Tue, 23 Feb 2016 17:26:48 +0000
4 Subject: [PATCH] amba_pl011: Don't use DT aliases for numbering
5
6 The pl011 driver looks for DT aliases of the form "serial<n>",
7 and if found uses <n> as the device ID. This can cause
8 /dev/ttyAMA0 to become /dev/ttyAMA1, which is confusing if the
9 other serial port is provided by the 8250 driver which doesn't
10 use the same logic.
11 ---
12 drivers/tty/serial/amba-pl011.c | 5 +++++
13 1 file changed, 5 insertions(+)
14
15 --- a/drivers/tty/serial/amba-pl011.c
16 +++ b/drivers/tty/serial/amba-pl011.c
17 @@ -2441,7 +2441,12 @@ static int pl011_setup_port(struct devic
18 if (IS_ERR(base))
19 return PTR_ERR(base);
20
21 + /* Don't use DT serial<n> aliases - it causes the device to
22 + be renumbered to ttyAMA1 if it is the second serial port in the
23 + system, even though the other one is ttyS0. The 8250 driver
24 + doesn't use this logic, so always remains ttyS0.
25 index = pl011_probe_dt_alias(index, dev);
26 + */
27
28 uap->old_cr = 0;
29 uap->port.dev = dev;