From 675c496d0f92b481ebe4abf4fb06eadad7789de6 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sat, 16 Oct 2021 12:50:21 +0200 Subject: [PATCH] clk: composite: Also consider .determine_rate for rate + mux composites Commit 69a00fb3d69706 ("clk: divider: Implement and wire up .determine_rate by default") switches clk_divider_ops to implement .determine_rate by default. This breaks composite clocks with multiple parents because clk-composite.c does not use the special handling for mux + divider combinations anymore (that was restricted to rate clocks which only implement .round_rate, but not .determine_rate). Alex reports: This breaks lot of clocks for Rockchip which intensively uses composites, i.e. those clocks will always stay at the initial parent, which in some cases is the XTAL clock and I strongly guess it is the same for other platforms, which use composite clocks having more than one parent (e.g. mediatek, ti ...) Example (RK3399) clk_sdio is set (initialized) with XTAL (24 MHz) as parent in u-boot. It will always stay at this parent, even if the mmc driver sets a rate of 200 MHz (fails, as the nature of things), which should switch it to any of its possible parent PLLs defined in mux_pll_src_cpll_gpll_npll_ppll_upll_24m_p (see clk-rk3399.c) - which never happens. Restore the original behavior by changing the priority of the conditions inside clk-composite.c. Now the special rate + mux case (with rate_ops having a .round_rate - which is still the case for the default clk_divider_ops) is preferred over rate_ops which have .determine_rate defined (and not further considering the mux). Fixes: 69a00fb3d69706 ("clk: divider: Implement and wire up .determine_rate by default") Reported-by: Alex Bee Signed-off-by: Martin Blumenstingl Link: https://lore.kernel.org/r/20211016105022.303413-2-martin.blumenstingl@googlemail.com Tested-by: Alex Bee Tested-by: Chen-Yu Tsai Signed-off-by: Stephen Boyd --- drivers/clk/clk-composite.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c index 0506046a5f4b..510a9965633b 100644 --- a/drivers/clk/clk-composite.c +++ b/drivers/clk/clk-composite.c @@ -58,11 +58,8 @@ static int clk_composite_determine_rate(struct clk_hw *hw, long rate; int i; - if (rate_hw && rate_ops && rate_ops->determine_rate) { - __clk_hw_set_clk(rate_hw, hw); - return rate_ops->determine_rate(rate_hw, req); - } else if (rate_hw && rate_ops && rate_ops->round_rate && - mux_hw && mux_ops && mux_ops->set_parent) { + if (rate_hw && rate_ops && rate_ops->round_rate && + mux_hw && mux_ops && mux_ops->set_parent) { req->best_parent_hw = NULL; if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) { @@ -107,6 +104,9 @@ static int clk_composite_determine_rate(struct clk_hw *hw, req->rate = best_rate; return 0; + } else if (rate_hw && rate_ops && rate_ops->determine_rate) { + __clk_hw_set_clk(rate_hw, hw); + return rate_ops->determine_rate(rate_hw, req); } else if (mux_hw && mux_ops && mux_ops->determine_rate) { __clk_hw_set_clk(mux_hw, hw); return mux_ops->determine_rate(mux_hw, req);