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 <ezequiel.garcia@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dbd2df859a