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Commit 03bc10ab authored by Boris Brezillon's avatar Boris Brezillon Committed by Michael Turquette
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clk: check ->determine/round_rate() return value in clk_calc_new_rates 



->determine_rate() and ->round_rate() can return the closest rate to the
requested one or an error code.
clk_calc_new_rates is assuming these functions can't return a negative
value, which leads to a undefined behavior when the clk implementation
returns such an error code.
Fix this by returning NULL in case ->determine_rate() or ->round_rate()
returned an error code.

Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: default avatarMichael Turquette <mturquette@linaro.org>
parent 45912431

drivers/clk/clk.c

+16 −7
Original line number Diff line number Diff line
@@ -1618,6 +1618,7 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk, 
	unsigned long min_rate;

	unsigned long max_rate;

	int p_index = 0;

	long ret;



	/* sanity */

	if (IS_ERR_OR_NULL(clk))
@@ -1633,15 +1634,23 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk, 
	/* find the closest rate and parent clk/rate */

	if (clk->ops->determine_rate) {

		parent_hw = parent ? parent->hw : NULL;

		new_rate = clk->ops->determine_rate(clk->hw, rate,

		ret = clk->ops->determine_rate(clk->hw, rate,

					       min_rate,

					       max_rate,

					       &best_parent_rate,

					       &parent_hw);

		if (ret < 0)

			return NULL;



		new_rate = ret;

		parent = parent_hw ? parent_hw->core : NULL;

	} else if (clk->ops->round_rate) {

		new_rate = clk->ops->round_rate(clk->hw, rate,

		ret = clk->ops->round_rate(clk->hw, rate,

					   &best_parent_rate);

		if (ret < 0)

			return NULL;



		new_rate = ret;

		if (new_rate < min_rate || new_rate > max_rate)

			return NULL;

	} else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {