From b61c43c09f5e2b9bf8f340034c5ef1db8c64efa5 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Mon, 2 Feb 2015 14:11:25 -0800 Subject: [PATCH] clk: clk_set_parent() with current parent shouldn't fail 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 Acked-by: Philipp Zabel Signed-off-by: Michael Turquette --- drivers/clk/clk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 42064cec2364..3e10cdff284b 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -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; -- 2.20.1