clk: Check parent for NULL in clk_change_rate

clk_change_rate() is accessing parent's rate without checking
if the parent exists at all. In case of root clocks this will
cause NULL pointer dereference.

This patch follows what clk_calc_new_rates() does in such
situation.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
This commit is contained in:
Pawel Moll 2012-06-08 14:04:06 +01:00 committed by Mike Turquette
parent 7975059db5
commit bf47b4fd8f

View File

@ -850,18 +850,21 @@ static void clk_change_rate(struct clk *clk)
{
struct clk *child;
unsigned long old_rate;
unsigned long best_parent_rate = 0;
struct hlist_node *tmp;
old_rate = clk->rate;
if (clk->parent)
best_parent_rate = clk->parent->rate;
if (clk->ops->set_rate)
clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);
clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
if (clk->ops->recalc_rate)
clk->rate = clk->ops->recalc_rate(clk->hw,
clk->parent->rate);
clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
else
clk->rate = clk->parent->rate;
clk->rate = best_parent_rate;
if (clk->notifier_count && old_rate != clk->rate)
__clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);