Re: [PATCH v5 3/3] soc: mediatek: mtk-svs: add thermal voltage compensation if needed

[Matthias Brugger]

On 11/02/2023 12:12, Roger Lu (陸瑞傑) wrote:
> Hi Matthias Sir,
>
> Sorry for the late reply.
>
> ... [snip] ...
>
> > > @@ -2127,6 +2123,7 @@ static struct svs_bank svs_mt8192_banks[] = {
> > >    		.type			= SVSB_LOW,
> > >    		.set_freq_pct		= svs_set_bank_freq_pct_v3,
> > >    		.get_volts		= svs_get_bank_volts_v3,
> > > +		.tzone_name		= "gpu1",
> > >    		.volt_flags		= SVSB_REMOVE_DVTFIXED_VOLT,
> > >    		.mode_support		= SVSB_MODE_INIT02,
> > >    		.opp_count		= MAX_OPP_ENTRIES,
> > > @@ -2144,6 +2141,10 @@ static struct svs_bank svs_mt8192_banks[] = {
> > >    		.core_sel		= 0x0fff0100,
> > >    		.int_st			= BIT(0),
> > >    		.ctl0			= 0x00540003,
> > > +		.tzone_htemp		= 85000,
> > > +		.tzone_htemp_voffset	= 0,
> > > +		.tzone_ltemp		= 25000,
> > > +		.tzone_ltemp_voffset	= 7,
> >
> > Which is the exact same tzone then in the other bank. Which brings me to a
> > good
> > point:
> > Is the tzone bank specific or the same for all banks?
>
> Thermal zone (tzone) isn't for all SVS banks. In other words, tzone is specific
> for corresponding DVFS domain like SVS GPU tzone is for GPU DVFS domain. Let's
> take MT8183 SVS and MT8192 SVS as examples.
>
> MT8192 SVS applies 2-line HW design (High/low 2 banks optimize the same DVFS
> domain). So, SVS GPU High/low bank uses the same GPU tzone.
>
> MT8183 SVS applies 1-line HW design (1 bank optimizes 1 DVFS domain)
> Therefore, SVS CPU/GPU/CCI bank use different tzone because they are different
> DVFS domain.
>
> > At least for mt8192 they are not. I suppose with this change to the code
> > mt8183
> > could take advantage of this on all it's banks as well.
> > In that case, can we
> > start to restructure the struct svs_bank to only have the tzone values
> > declared
> > once?
>
> Since tzone isn't for all banks, we cannot declare it once for all IC supports
> from this point of view.

Thanks for clarification, applied now.

> > Background is that I'm very unhappy with the svs_bank data strucutre. It
> > seems
> > like a "throw it all in here". It should be structured for functional parts
> > of
> > the banks. Maybe using structs, maybe unions where possible. In any case
> > having
> > a flat struct of over 50 members isn't really what we want.
>
> My apology. We'll structure svs_bank for functional parts of them.
>
> > Regards,
> > Matthias