Re: BD71847 clk driver disables clk-32k-out causing RTC/WDT failure

[Marek Vasut]

On 9/8/22 18:00, Tim Harvey wrote:
> On Thu, Sep 1, 2022 at 9:14 PM Matti Vaittinen <mazziesaccount@xxxxxxxxx> wrote:
> > Hi Tim,
> >
> > On 9/2/22 01:23, Tim Harvey wrote:
> > > Greetings,
> > >
> > > I've found that the bd71847 clk driver (CONFIG_COMMON_CLK_BD718XX
> > > drivers/clk/clk-bd718x7.c) disables clk-32k-out (the BD71847 C32K_OUT
> > > pin) which is connected IMX8MM RTC_XTALI which ends up disabling the
> > > IMX RTC as well as the IMX WDOG functionality.
> >
> > //snip
> >
> > > This happens via clk_unprepare_unused() as nothing is flagging the
> > > clk-32k-out as being used. What should be added to the device-tree to
> > > signify that this clk is indeed necessary and should not be disabled?
> >
> > I have seen following proposal from Marek Vasut:
> >
> > https://lore.kernel.org/all/20220517235919.200375-1-marex@xxxxxxx/T/#m52d6d0831bf43d5f293e35cb27f3021f278d0564
> >
> > I am not sure if the discussion is completed though. I guess it was
> > agreed this was needed/usefull and maybe the remaining thing to decide
> > was just the property naming.
> >
> > Best Regards
> >          -- Matti
>
> Thanks Matti,
>
> Marek - has there been any progress on determining how best to keep
> certain clocks from being disabled?

No. You can read the discussion above.