clk: clk_set_parent() with current parent shouldn't fail (b61c43c0) · Commits · e / devices / android_kernel_fairphone_FP5

If a driver calls clk_set_parent(clk, parent) and parent is the current parent of clk we shouldn't fail in any case. Unfortunately if clk is a read-only mux we return -ENOSYS because we think we can't change the parent, except for in this special case where we don't actually need to change the parent at all. Return 0 in such a situation. Signed-off-by:

Stephen Boyd <sboyd@codeaurora.org> Acked-by:

Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by:

Michael Turquette <mturquette@linaro.org>

drivers/clk/clk.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -2055,16 +2055,18 @@ static int clk_core_set_parent(struct clk_core clk, struct clk_core parent)
		if (!clk)
		return 0;

		/* verify ops for for multi-parent clks */
		if ((clk->num_parents > 1) && (!clk->ops->set_parent))
		return -ENOSYS;

		/* prevent racing with updates to the clock topology */
		clk_prepare_lock();

		if (clk->parent == parent)
		goto out;

		/* verify ops for for multi-parent clks */
		if ((clk->num_parents > 1) && (!clk->ops->set_parent)) {
		ret = -ENOSYS;
		goto out;
		}

		/* check that we are allowed to re-parent if the clock is in use */
		if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
		ret = -EBUSY;