Re: [Qemu-devel] [PATCH v2] hw/misc/zynq_slcr: Change CPU clock rate for Linux boots

[Guenter Roeck]

Peter,

On 09/13/2015 01:47 PM, Peter Maydell wrote:
> On 13 September 2015 at 21:22, Peter Crosthwaite
> <address@hidden> wrote:
> > On Sat, Sep 12, 2015 at 2:06 PM, Guenter Roeck <address@hidden> wrote:
> > > The Linux kernel only accepts 333334 Khz and 666667 Khz clock rates, and
> > > may crash if the actual clock rate is too low. The clock rate used to be
> > > (ps-clk-frequency * 26 / 4), which resulted in a CPU frequency of
> > > 216666 Khz if ps-clk-frequency was set to 33333333 Hz. Change it to
> > > (ps-clk-frequency * 20 / 2) = 333333 Khz for to make Linux happy.
> > > Limit the change to Linux boots only.
> > >
> > > Signed-off-by: Guenter Roeck <address@hidden>
> >
> > Reviewed-by: Peter Crosthwaite <address@hidden>
> >
> > Can this go via target-arm? (cc PMM).
> >
> > There may be more changes worth making on is_linux. I don't have the
> > patch with the full list of FSBL-related SLCR changes handy and can't
> > seem to find it in any modern Yocto trees. Wondering if Yocto still
> > supports booting Zynq without FSBL (Nathan/Alistair may know more)?
>
> I'd prefer us not to propagate lots of "only if Linux boot"
> changes into devices. The GIC *must* have these because the
> kernel can't configure it otherwise from non-secure mode.
> I'm not sure that applies here.

Not sure I understand. Is this a NACK ?

Thanks,
Guenter