Re: [PATCH 4/9] clk: imx: add pllv4 support

From: Stephen Boyd
Date: Fri Jun 30 2017 - 20:36:53 EST


On 06/20, Dong Aisheng wrote:
> On Mon, Jun 19, 2017 at 06:59:17PM -0700, Stephen Boyd wrote:
> > On 05/15, Dong Aisheng wrote:
> > > +
> > > + if (clk_pllv4_is_enabled(hw)) {
> > > + WARN(1, "clk_pllv4: can't change rate when pll is enabled");
> > > + return -EINVAL;
> >
> > Sad, CLK_SET_RATE_GATE isn't working for you I suppose?
> >
>
> CLK_SET_RATE_GATE can't work in early stage before running clk_disable_unused.
> At that point, the clock tree state is still not consistent with HW.
> e.g. prepare/enable count is still zero but it's actually enabled due to
> reset state or bootloader.
>
> The code here is adding a double check in case user sets rate in early stage.
>
> However, probably it could also be moved into clock core as it's not platform
> dependant behavior?
>

Ok. It would be good to fix the core framework to synchronize the
prepared/enabled state at registration time so we don't need this
check in the driver.

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