Re: [PATCH 01/11] clk: sunxi-ng: mux: Fix determine_rate for mux clocks with pre-dividers
From: Maxime Ripard <hidden>
Date: 2017-01-26 09:55:33
Also in:
linux-arm-kernel, linux-clk, lkml
Hi Chen-Yu, On Tue, Jan 24, 2017 at 10:32:20AM +0800, Chen-Yu Tsai wrote:
quoted hunk ↗ jump to hunk
The determine_rate helper used ccu_mux_helper_adjust_parent_for_prediv() to adjust the parent_rate to account for pre-dividers, but then passed the pristine parent clock rate from clk_hw_get_rate() to the round() callback, thereby ignoring the pre-divider adjustment. In addition, it was saving the adjusted parent rate back into struct clk_rate_request. This patch fixes this by saving the pristine parent clock rate, and adding a copy that is adjusted and passed to the round() callback. The pristine copy, if it is the best solution, would be saved back to struct clk_rate_request. Signed-off-by: Chen-Yu Tsai <redacted> --- drivers/clk/sunxi-ng/ccu_mux.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c index 858a48621631..3445041894e7 100644 --- a/drivers/clk/sunxi-ng/ccu_mux.c +++ b/drivers/clk/sunxi-ng/ccu_mux.c@@ -71,7 +71,7 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common, unsigned int i; for (i = 0; i < clk_hw_get_num_parents(hw); i++) { - unsigned long tmp_rate, parent_rate; + unsigned long tmp_rate, parent_rate, adj_parent_rate; struct clk_hw *parent; parent = clk_hw_get_parent_by_index(hw, i);@@ -79,10 +79,11 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common, continue; parent_rate = clk_hw_get_rate(parent); + adj_parent_rate = parent_rate; ccu_mux_helper_adjust_parent_for_prediv(common, cm, i, - &parent_rate); + &adj_parent_rate); - tmp_rate = round(cm, clk_hw_get_rate(parent), req->rate, data); + tmp_rate = round(cm, parent_rate, req->rate, data);
Shouldn't you use the adjusted rate here too? Thanks, Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com