Re: [linux-next:master 9185/10024] drivers/pmdomain/mediatek/airoha-cpu-pmdomain.c:59:2: error: write to reserved register 'R7'

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

On Mon, Jan 20, 2025 at 03:52:09PM +0100, Christian Marangi (Ansuel) wrote:
> Il giorno lun 20 gen 2025 alle ore 14:44 Sudeep Holla
> <sudeep.holla@arm.com> ha scritto:
> >
> > On Mon, Jan 20, 2025 at 02:37:19PM +0100, Christian Marangi (Ansuel) wrote:
> > > Il giorno lun 20 gen 2025 alle ore 14:34 Sudeep Holla
> > > <sudeep.holla@arm.com> ha scritto:
> > > >
> > > > On Mon, Jan 20, 2025 at 02:01:30PM +0100, Ulf Hansson wrote:
> > > > > + Sudeep,
> > > > >
> > > > > On Mon, 20 Jan 2025 at 11:37, Christian Marangi (Ansuel)
> > > > > <ansuelsmth@gmail.com> wrote:
> >
> > [...]
> >
> > > > > >
> > > > > > Mhhhh.... Any idea how to fix this? Maybe we have to exclude some flags?
> > > > > > Error is "error: write to reserved register 'R7'" and I guess it's very specific
> > > > > > to some kind of ARM ERRATA.
> > > > >
> > > > > I don't know to be honest. The arm-scmi transport driver
> > > > > (drivers/firmware/arm_scmi/transports/smc.c) is having similar calls
> > > > > with 9 parameters to arm_smccc_1_1_invoke(). Not sure why it's a
> > > > > problem here and not there?
> > > > >
> > > >
> > > > I think it is known issue and must be solved with the below patch if my
> > > > understanding is right.
> > > >
> > >
> > > If it's a known issue and affects also other use of smcc why we need
> > > specific fix in the driver makefile instead of a more generic one.
> > >
> >
> > IIUC, arm_smccc_1_1_invoke() is a macro which can be used anywhere.
> > There are reasons why we can't move it to a module and export it.
> >
> > > Do you have a link for the known issue?
> > >
> >
> > Nothing handy, but quick google search gave me this:
> > https://bugs.llvm.org/show_bug.cgi?id=45826
> >
> 
> If only these test report were easy to report instead of me having to build
> the massive llvm-20 dev version...
> 
> Any hint if anyone knows if precompiled cross tool are present around the web
> (with llvm-20?)

I can test it I guess as I have clang v20. Let me give it a go.

-- 
Regards,
Sudeep