From f6b6f52b583003ad443d5709c56b8858466c4268 Mon Sep 17 00:00:00 2001
From: Lee Jones <lee.jones@linaro.org>
Date: Thu, 9 May 2013 13:50:55 +0100
Subject: serial: pl011: protect attribute read from NULL platform data struct

It's completely feasible that platform data will be empty i.e. when
booting with Device Tree with no device AUXDATA. So we must protect
it's use in these use-cases, or risk a kernel Oops.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8ab70a6..e2774f9 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -332,7 +332,7 @@ static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *
 		dmaengine_slave_config(chan, &rx_conf);
 		uap->dmarx.chan = chan;
 
-		if (plat->dma_rx_poll_enable) {
+		if (plat && plat->dma_rx_poll_enable) {
 			/* Set poll rate if specified. */
 			if (plat->dma_rx_poll_rate) {
 				uap->dmarx.auto_poll_rate = false;
-- 
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