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Re: [RFC PATCH v2] clk: move check of CLK_SET_RATE_GATE flag to clk_propagate_rate_change()

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Quoting jiada_wang@mentor.com (2016-07-10 22:33:28)
> From: Jiada Wang <jiada_wang@mentor.com>
> 
> Previously CLK_SET_RATE_GATE flag is only checked in clk_set_rate()
> which only ensures the clock being called by clk_set_rate() won't
> change rate when it has been prepared if CLK_SET_RATE_GATE flag is set.
> But a clk_set_rate() request may propagate rate change to these clocks
> from the requested clock's topmost parent clock to all its offsprings,
> when any one of these clocks has CLK_SET_RATE_GATE flag set
> and it has been prepared, the clk_set_rate() request should fail.
> 
> This patch moves check of CLK_SET_RATE_GATE flag to
> clk_propagate_rate_change() to ensure all affected clocks will
> be checked if their rate will be changed after clk_set_rate().
> 
> Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
> ---

What's different in version 2? It's tradition to put a little version
changelog here, below the "---" line and above the "diff --git a/..."
line.

Regards,
Mike

>  drivers/clk/clk.c |    6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 820a939..2f930c8 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -1437,6 +1437,9 @@ static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
>         if (core->rate == core->new_rate)
>                 return NULL;
>  
> +       if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
> +               return core;
> +
>         if (core->notifier_count) {
>                 ret = __clk_notify(core, event, core->rate, core->new_rate);
>                 if (ret & NOTIFY_STOP_MASK)
> @@ -1571,9 +1574,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
>         if (rate == clk_core_get_rate_nolock(core))
>                 return 0;
>  
> -       if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
> -               return -EBUSY;
> -
>         /* calculate new rates and get the topmost changed clock */
>         top = clk_calc_new_rates(core, rate);
>         if (!top)
> -- 
> 1.7.9.5
> 
> 

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[RFC PATCH v2] clk: move check of CLK_SET_RATE_GATE flag to clk_propagate_rate_change() <jiada_wang@mentor.com> - 2016-07-11 07:40 +0200
  Re: [RFC PATCH v2] clk: move check of CLK_SET_RATE_GATE flag to  clk_propagate_rate_change() Michael Turquette <mturquette@baylibre.com> - 2016-07-13 00:40 +0200
    Re: [RFC PATCH v2] clk: move check of CLK_SET_RATE_GATE flag to clk_propagate_rate_change() Jiada Wang <jiada_wang@mentor.com> - 2016-07-14 07:20 +0200

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