[PATCH] clk: Check parent for NULL in clk_change_rate
From: Pawel Moll <hidden>
Date: 2012-06-08 13:04:21
Also in:
lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
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 <redacted> --- Hi Mike, This is something I had to workaround to get Versatile Express working with the common clock framework - my root clocks aren't are variable (as in: non fixed). I'm told that this might have been already fixed - if that's the case simply ignore this patch. Also I'm not saying it's the best way of solving the issue :-) Cheers! Pawel drivers/clk/clk.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 687b00d..cf53069 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c@@ -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);
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1.7.9.5