clk: sunxi: fix uninitialized access

commit 4e90345 upstream.

gcc-8 reports an uninitialized variable access in a code path
that we would see with incorrect DTB input:

drivers/clk/sunxi/clk-sun8i-bus-gates.c: In function 'sun8i_h3_bus_gates_init':
drivers/clk/sunxi/clk-sun8i-bus-gates.c:85:27: error: 'clk_parent' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This works around by skipping invalid input and printing a warning
instead if it ever happens. The problem was apparently part of the
initiali driver submission, but older compilers don't notice it.

Fixes: ab6e23a ("clk: sunxi: Add H3 clocks support")
Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Maxime Ripard <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: arndb

drivers/clk/sunxi/clk-sun8i-bus-gates.c

@@ -78,6 +78,10 @@ static void __init sun8i_h3_bus_gates_init(struct device_node *node)
 			clk_parent = APB1;
 		else if (index >= 96 && index <= 127)
 			clk_parent = APB2;
+		else {
+			WARN_ON(true);
+			continue;
+		}
 
 		clk_reg = reg + 4 * (index / 32);
 		clk_bit = index % 32;