[PATCH] serial: of-serial: zero-out struct of_serial_info

[Florian Fainelli <f.fainelli@gmail.com>]

of_platform_serial_probe() invokes of_platform_serial_setup() with a
kmalloc'd struct of_serial_info cookie, which is not much of a problem
for most of the struct of_serial_info fields we access but info->clk.

On platforms which do not provide a clock phandle for their UART nodes
but do provide a 'clock-frequency' property, we basically leave the
info->clk variable uninitialized, and this craps out during
suspend/resume with oopses, crashes or warnings in the clock code.

Fix this by using kzalloc() which also zeroes-out the structure and
provides an initialized info->clk member set to NULL.

Fixes: 2dea53bf57783 ("serial: of-serial: add PM suspend/resume support")
Fixes: e34b9c94b6e8d ("[POWERPC] of_serial: add port type checking")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
Greg, Jiri,

This fixes a regression introduced in 3.18-rc1, thanks!

 drivers/tty/serial/of_serial.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 8bc2563335ae..56982da4a9e9 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -158,7 +158,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
 		return -EBUSY;
 
-	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (info == NULL)
 		return -ENOMEM;
 
-- 
1.9.1