Re: [PATCH 1/2] clk: honor CLK_MUX_ROUND_CLOSEST in generic clk mux

From: Ezequiel Garcia
Date: Tue Apr 24 2018 - 10:04:33 EST


On 9 April 2018 at 10:59, Jerome Brunet <jbrunet@xxxxxxxxxxxx> wrote:
>
> CLK_MUX_ROUND_CLOSEST is part of the clk_mux documentation but clk_mux
> directly calls __clk_mux_determine_rate(), which overrides the flag.
> As result, if clk_mux is instantiated with CLK_MUX_ROUND_CLOSEST, the
> flag will be ignored and the clock rounded down.
>
> To solve this, this patch expose clk_mux_determine_rate_flags() in the
> clk-provider API and uses it in the determine_rate() callback of clk_mux.
>
> Fixes: 15a02c1f6dd7 ("clk: Add __clk_mux_determine_rate_closest")
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
> drivers/clk/clk-mux.c | 10 +++++++++-
> drivers/clk/clk.c | 7 ++++---
> include/linux/clk-provider.h | 3 +++
> 3 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/clk-mux.c b/drivers/clk/clk-mux.c
> index ac4a042f8658..1628b93655ed 100644
> --- a/drivers/clk/clk-mux.c
> +++ b/drivers/clk/clk-mux.c
> @@ -112,10 +112,18 @@ static int clk_mux_set_parent(struct clk_hw *hw, u8 index)
> return 0;
> }
>
> +static int clk_mux_determine_rate(struct clk_hw *hw,
> + struct clk_rate_request *req)
> +{
> + struct clk_mux *mux = to_clk_mux(hw);
> +
> + return clk_mux_determine_rate_flags(hw, req, mux->flags);
> +}
> +
> const struct clk_ops clk_mux_ops = {
> .get_parent = clk_mux_get_parent,
> .set_parent = clk_mux_set_parent,
> - .determine_rate = __clk_mux_determine_rate,
> + .determine_rate = clk_mux_determine_rate,
> };
> EXPORT_SYMBOL_GPL(clk_mux_ops);
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index ea67ac81c6f9..7af555f0e60c 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -426,9 +426,9 @@ static bool mux_is_better_rate(unsigned long rate, unsigned long now,
> return now <= rate && now > best;
> }
>
> -static int
> -clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
> - unsigned long flags)
> +int clk_mux_determine_rate_flags(struct clk_hw *hw,
> + struct clk_rate_request *req,
> + unsigned long flags)
> {
> struct clk_core *core = hw->core, *parent, *best_parent = NULL;
> int i, num_parents, ret;
> @@ -488,6 +488,7 @@ clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req,
>
> return 0;
> }
> +EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
>

Why do we need to export this?

> struct clk *__clk_lookup(const char *name)
> {
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index 210a890008f9..1d25e149c1c5 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -765,6 +765,9 @@ int __clk_mux_determine_rate(struct clk_hw *hw,
> int __clk_determine_rate(struct clk_hw *core, struct clk_rate_request *req);
> int __clk_mux_determine_rate_closest(struct clk_hw *hw,
> struct clk_rate_request *req);
> +int clk_mux_determine_rate_flags(struct clk_hw *hw,
> + struct clk_rate_request *req,
> + unsigned long flags);
> void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent);
> void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
> unsigned long max_rate);
> --
> 2.14.3
>

Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>

Thanks!
--
Ezequiel GarcÃa, VanguardiaSur
www.vanguardiasur.com.ar