[SERIAL] Add comment about early_serial_setup()

early_serial_setup() must not be called after console initialisation.
Add a comment prior to the function explicitly stating this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 244e8ff11977..7aca22c9976d 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -2326,6 +2326,12 @@ static struct uart_driver serial8250_reg = {
         .cons                   = SERIAL8250_CONSOLE,
 };
 
+/*
+ * early_serial_setup - early registration for 8250 ports
+ *
+ * Setup an 8250 port structure prior to console initialisation.  Use
+ * after console initialisation will cause undefined behaviour.
+ */
 int __init early_serial_setup(struct uart_port *port)
 {
         if (port->line >= ARRAY_SIZE(serial8250_ports))