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Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0160-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch')
-rw-r--r--target/linux/brcm2708/patches-4.4/0160-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch29
1 files changed, 29 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0160-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch b/target/linux/brcm2708/patches-4.4/0160-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch
new file mode 100644
index 0000000..344fbd9
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0160-amba_pl011-Don-t-use-DT-aliases-for-numbering.patch
@@ -0,0 +1,29 @@
+From 00dba6ec2ac004fc17075febd4504646eb3dc543 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Tue, 23 Feb 2016 17:26:48 +0000
+Subject: [PATCH 160/170] amba_pl011: Don't use DT aliases for numbering
+
+The pl011 driver looks for DT aliases of the form "serial<n>",
+and if found uses <n> as the device ID. This can cause
+/dev/ttyAMA0 to become /dev/ttyAMA1, which is confusing if the
+other serial port is provided by the 8250 driver which doesn't
+use the same logic.
+---
+ drivers/tty/serial/amba-pl011.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/drivers/tty/serial/amba-pl011.c
++++ b/drivers/tty/serial/amba-pl011.c
+@@ -2313,7 +2313,12 @@ static int pl011_setup_port(struct devic
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
++ /* Don't use DT serial<n> aliases - it causes the device to
++ be renumbered to ttyAMA1 if it is the second serial port in the
++ system, even though the other one is ttyS0. The 8250 driver
++ doesn't use this logic, so always remains ttyS0.
+ index = pl011_probe_dt_alias(index, dev);
++ */
+
+ uap->old_cr = 0;
+ uap->port.dev = dev;