On Wed, 2018-11-14 at 23:57 +0100, Martin Blumenstingl wrote:
> We don't want the common clock framework to disable the "cpu_clk" if
> it's not used by any device. The cpufreq-dt driver does not enable the
> CPU clocks. However, even if it would we would still want the CPU clock
> to be enabled at all times because the CPU clock is also required even
> if we disable CPU frequency scaling on a specific board.
>
> The reason why we want the CPU clock to be enabled is a clock further up
> in the tree:
> Since commit 6f888e7bc7bd58 ("clk: meson: clk-pll: add enable bit") the
> sys_pll can be disabled. However, since the CPU clock is derived from
> sys_pll we don't want sys_pll to get disabled. The common clock
> framework takes care of that for us by enabling all parent clocks of our
> CPU clock when we mark the CPU clock with CLK_IS_CRITICAL.
>
> Until now this is not a problem yet because all clocks in the CPU
> clock's tree (including sys_pll) are read-only. However, once we allow
> modifications to the clocks in that tree we will need this.
>
> Signed-off-by: Martin Blumenstingl <martin.blumensti...@googlemail.com>
> ---
> drivers/clk/meson/meson8b.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/meson/meson8b.c b/drivers/clk/meson/meson8b.c
> index 8a3c346e110d..d566dd5bc567 100644
> --- a/drivers/clk/meson/meson8b.c
> +++ b/drivers/clk/meson/meson8b.c
> @@ -646,7 +646,8 @@ static struct clk_regmap meson8b_cpu_clk = {
> "cpu_scale_out_sel" },
> .num_parents = 2,
> .flags = (CLK_SET_RATE_PARENT |
> - CLK_SET_RATE_NO_REPARENT),
> + CLK_SET_RATE_NO_REPARENT |
> + CLK_IS_CRITICAL),
> },
> };
>
Acked-by: Jerome Brunet <jbru...@baylibre.com>
