On Mon, Nov 11, 2024 at 06:39:48PM +0530, Jagadeesh Kona wrote:
>
>
> On 10/17/2024 9:12 PM, Brian Masney wrote:
> > On Thu, Oct 17, 2024 at 02:58:31PM +0530, Jagadeesh Kona wrote:
> >> + cpu0_opp_table: opp-table-cpu0 {
> >> + compatible = "operating-points-v2";
> >> + opp-shared;
> >> +
> >> + cpu0_opp_1267mhz: opp-1267200000 {
> >> + opp-hz = /bits/ 64 <1267200000>;
> >> + opp-peak-kBps = <6220800 29491200>;
> >> + };
> >> +
> >> + cpu0_opp_1363mhz: opp-1363200000 {
> >> + opp-hz = /bits/ 64 <1363200000>;
> >> + opp-peak-kBps = <6220800 29491200>;
> >> + };
> >
> > [snip]
> >
> >> + cpu4_opp_table: opp-table-cpu4 {
> >> + compatible = "operating-points-v2";
> >> + opp-shared;
> >> +
> >> + cpu4_opp_1267mhz: opp-1267200000 {
> >> + opp-hz = /bits/ 64 <1267200000>;
> >> + opp-peak-kBps = <6220800 29491200>;
> >> + };
> >> +
> >> + cpu4_opp_1363mhz: opp-1363200000 {
> >> + opp-hz = /bits/ 64 <1363200000>;
> >> + opp-peak-kBps = <6220800 29491200>;
> >> + };
> >
> > There's no functional differences in the cpu0 and cpu4 opp tables. Can
> > a single table be used?
> >
> > This aligns with my recollection that this particular SoC only has the
> > gold cores.
> >
> > Brian
> >
>
> Thanks Brian for your review. Sorry for the delayed response.
>
> We require separate OPP tables for CPU0 and CPU4 to allow independent
> scaling of DDR and L3 frequencies for each CPU domain, with the final
> DDR and L3 frequencies being an aggregate of both.
>
> If we use a single OPP table for both CPU domains, then _allocate_opp_table() [1]
> won't be invoked for CPU4. As a result both CPU devices will end up in sharing
> the same ICC path handle, which could lead to one CPU device overwriting the bandwidth
> votes of other.
All of this should be a part of the commit message.
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/opp/core.c#n1588
>
> Thanks,
> Jagadeesh
>
--
With best wishes
Dmitry
