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>
This commit is contained in:
Lee Jones 2013-05-09 13:50:55 +01:00 committed by Greg Kroah-Hartman
parent 383d2fc96c
commit f6b6f52b58

View File

@ -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;