aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch')
-rw-r--r--target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch28
1 files changed, 28 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch b/target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch
new file mode 100644
index 0000000000..b421ba9cdc
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0843-serial-8250-bcm2835aux-defer-if-clock-is-zero.patch
@@ -0,0 +1,28 @@
+From 80163961af8e31a2045271c5a12adaae620445e1 Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.com>
+Date: Thu, 2 Jul 2020 13:53:20 +0100
+Subject: [PATCH] serial: 8250: bcm2835aux - defer if clock is zero
+
+See: https://github.com/raspberrypi/linux/issues/3700
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.com>
+---
+ drivers/tty/serial/8250/8250_bcm2835aux.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
++++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
+@@ -92,6 +92,13 @@ static int bcm2835aux_serial_probe(struc
+ */
+ data->uart.port.uartclk = clk_get_rate(data->clk) * 2;
+
++ /* The clock is only queried at probe time, which means we get one shot
++ * at this. A zero clock is never going to work and is almost certainly
++ * due to a parent not being ready, so prefer to defer.
++ */
++ if (!data->uart.port.uartclk)
++ return -EPROBE_DEFER;
++
+ /* register the port */
+ ret = serial8250_register_8250_port(&data->uart);
+ if (ret < 0) {