Re: Question: why call clk_prepare in pm_clk_acquire

[Sudeep Holla <sudeep.holla@arm.com>]

On Mon, Sep 12, 2022 at 06:58:49PM +0100, Geert Uytterhoeven wrote:
> Hi Sudeep,
> 
> CC Dien Pham
> 
> On Mon, Sep 12, 2022 at 6:49 PM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Fri, Sep 9, 2022 at 4:51 PM Sudeep Holla <sudeep.holla@arm.com> wrote:
> > > On Fri, Sep 09, 2022 at 01:12:03PM +0200, Ulf Hansson wrote:
> > > > On Thu, 8 Sept 2022 at 19:38, Sudeep Holla <sudeep.holla@arm.com> wrote:
> > > > > On Thu, Sep 08, 2022 at 04:37:13PM +0200, Ulf Hansson wrote:
> > > > > > On Thu, 8 Sept 2022 at 09:33, Peng Fan <peng.fan@nxp.com> wrote:
> > > > > > > We are facing an issue clk_set_rate fail with commit a3b884cef873 ("firmware:
> > > > > > > arm_scmi: Add clock management to the SCMI power domain") ,
> > > > > >
> > > > > > Hmm, I wonder about the main reason behind that commit. Can we revert
> > > > > > it or is there some platform/driver that is really relying on it?
> > > > > >
> > > > >
> > > > > IIUC, at the time of the commit, it was needed on some Renesas platform.
> > > > > Not sure if it is still used or not.
> > > >
> > > > Okay! Maybe Nico remembers more, as he authored the patch...
> > > >
> > >
> > > May be, or even check with Renesas team who tested his patch.
> >
> > I'm not aware of Renesas platforms using SCMI...
> 
> Upon closer look, Diep Pham did report a build issue in the SCMI code, so
> perhaps Diep knows more...
> 

Yes indeed, Diep Pham tested the original patch IIRC and also has reported
few bugs in SCMI clock code which are fixed. Hence I know it is used by
Renesas.

Hi Peng,

Absence of DTS changes indicate nothing. I am aware of couple of vendors
who use SCMI on several platforms and do report issues regularly and help
in review of the code. So DTS is not a good indicator of SCMI usage
unfortunately. On reason could be that since it is a firmware, bootloaders
can detect and update DTS, just my thought and may differ from the reality.

-- 
Regards,
Sudeep