Re: [RFC PATCH v2] clk: move check of CLK_SET_RATE_GATE flag to clk_propagate_rate_change()
From: Michael Turquette
Date: Tue Jul 12 2016 - 18:29:58 EST
Quoting jiada_wang@xxxxxxxxxx (2016-07-10 22:33:28)
> From: Jiada Wang <jiada_wang@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> ---
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
>
>