[U-Boot] [PATCH v4 2/2] TI: DaVinci DA850 EVM: support passing maximum allowed cpu clock rate information to kernel

Nori, Sekhar nsekhar at ti.com
Wed Sep 29 07:54:18 CEST 2010


Hi Ben,

On Tue, Sep 28, 2010 at 19:31:02, Ben Gardiner wrote:
> On Fri, Sep 24, 2010 at 1:10 AM, Nori, Sekhar <nsekhar at ti.com> wrote:
> > Hello All,
> >
> > On Fri, Aug 27, 2010 at 10:44:58, Nori, Sekhar wrote:
> >> The TI DA850/OMAP-L138/AM18x EVM can be populated with devices
> >> having different maximum allowed CPU clock rating.
> >>
> >> The maximum clock the chip can support can only be determined from
> >> the label on the package (not software readable).
> >>
> >> Introduce a method to pass the maximum allowed clock rate information
> >> to kernel using ATAG_REVISION. The kernel uses this information to
> >> determine the maximum cpu clock rate reachable using cpufreq.
> >>
> >> Note that U-Boot itself does not set the CPU clock rate. The CPU
> >> clock is setup by a primary bootloader ("UBL"). The rate setup by
> >> UBL could be different from the maximum clock rate supported by the
> >> device.
> >
> > Any more feedback on this patch? There are couple of kernel patches
> > which depend on this, that's why I ask.
>
> FWIW: it's fine with me.
>
> Applies cleanly to 3df61957938586c512c17e72d83551d190400981 of u-boot/next.
>
> Tested on da850evm -- bootm of linux uImage works with the patch
> 'da850evm: fix linux bootparam address' aplied.
>
> The kernel uImage used did not have support for parsing the
> ATAG_REVISION information since that patch has not been posted to the
> davinci-linux list.
>
> Tested-by: Ben Gardiner <bengardiner at nanometrics.ca>

Thanks for the testing!

Regards,
Sekhar



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