drivers: sh: clk: Avoid crashes when passing NULL clocks
authorGeert Uytterhoeven <geert+renesas@glider.be>
Thu, 19 Nov 2015 18:32:06 +0000 (19:32 +0100)
committerSimon Horman <horms+renesas@verge.net.au>
Tue, 24 Nov 2015 02:49:18 +0000 (11:49 +0900)
Several clock API functions handle NULL clocks when the Common Clock
Framework is used, while their legacy SH counterparts don't, and would
just crash when a NULL clock is passed.

Add NULL checks to clk_get_rate(), clk_set_rate(), clk_get_parent(), and
clk_round_rate(), to avoid different behavior in drivers shared between
legacy and CCF-based platforms.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
drivers/sh/clk/core.c

index 6bf973bd965408c738fe92e518652dd23066a294..92863e3818e5c726ec739b66d430c613e65a6f67 100644 (file)
@@ -469,6 +469,9 @@ void clk_enable_init_clocks(void)
 
 unsigned long clk_get_rate(struct clk *clk)
 {
+       if (!clk)
+               return 0;
+
        return clk->rate;
 }
 EXPORT_SYMBOL_GPL(clk_get_rate);
@@ -478,6 +481,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
        int ret = -EOPNOTSUPP;
        unsigned long flags;
 
+       if (!clk)
+               return 0;
+
        spin_lock_irqsave(&clock_lock, flags);
 
        if (likely(clk->ops && clk->ops->set_rate)) {
@@ -535,12 +541,18 @@ EXPORT_SYMBOL_GPL(clk_set_parent);
 
 struct clk *clk_get_parent(struct clk *clk)
 {
+       if (!clk)
+               return NULL;
+
        return clk->parent;
 }
 EXPORT_SYMBOL_GPL(clk_get_parent);
 
 long clk_round_rate(struct clk *clk, unsigned long rate)
 {
+       if (!clk)
+               return 0;
+
        if (likely(clk->ops && clk->ops->round_rate)) {
                unsigned long flags, rounded;