Re: [PATCH v3 12/12] clk: mediatek: Allow changing PLL rate when it is off
From: Stephen Boyd
Date: Fri Dec 14 2018 - 17:01:26 EST
Quoting Weiyi Lu (2018-12-09 23:32:40)
> From: James Liao <jamesjj.liao@xxxxxxxxxxxx>
> Some modules may need to change its clock rate before turn on it.
> So changing PLL's rate when it is off should be allowed.
> This patch removes PLL enabled check before set rate, so that
> PLLs can set new frequency even if they are off.
> On MT8173 for example, ARMPLL's enable bit can be controlled by
> other HW. That means ARMPLL may be turned on even if we (CPU / SW)
> set ARMPLL's enable bit as 0. In this case, SW may want and can
> still change ARMPLL's rate by changing its pcw and postdiv settings.
> But without this patch, new pcw setting will not be applied because
> its enable bit is 0.
> (am from https://patchwork.kernel.org/patch/9411983/)
> Signed-off-by: James Liao <jamesjj.liao@xxxxxxxxxxxx>
> Acked-by: Michael Turquette <mturuqette@xxxxxxxxxxxx>
> Signed-off-by: Weiyi Lu <weiyi.lu@xxxxxxxxxxxx>