From: Ezequiel Garcia Date: Tue, 7 May 2013 11:27:16 +0000 (-0300) Subject: serial: 8250_dw: Add valid clk pointer check X-Git-Tag: v4.0~4003^2~12 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=dbd2df859a4d992ccbceeb22c37f6a6c4aa4dc01;p=platform%2Fkernel%2Flinux-amlogic.git serial: 8250_dw: Add valid clk pointer check Commit ffc3ae6dd "serial: 8250_dw: Enable runtime PM" introduced runtime PM management, which enables/disables the clk without checking if the clk is valid. However, this driver allows to be probed without a defined clk, using clock-frequency, as a fallback. Therefore, on platforms that are device tree probed using clock-frequency instead of clk, we get an ugly NULL pointer dereference. This patch fixes it by simply adding a check before accessing the clk api. Signed-off-by: Ezequiel Garcia Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index beaa283..0b0eef9 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -338,7 +338,8 @@ static int dw8250_runtime_suspend(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); - clk_disable_unprepare(data->clk); + if (!IS_ERR(data->clk)) + clk_disable_unprepare(data->clk); return 0; } @@ -347,7 +348,8 @@ static int dw8250_runtime_resume(struct device *dev) { struct dw8250_data *data = dev_get_drvdata(dev); - clk_prepare_enable(data->clk); + if (!IS_ERR(data->clk)) + clk_prepare_enable(data->clk); return 0; }