atombios powerplay cac table

atombios powerplay cac table

[Sylvain BERTRAND]

Hi,

Which GPU generations/families do use the "new" powerplay CAC
table, defined when the atombios platform capabilities have the
ATOM_PP_PLATFORM_CAP_NEW_CAC_VOLTAGE flag?

----

On drm-next-3.13 branch, commit
70471860ff9f335c60c004d42ebd48945bfa5403, I noticed the
following:
For the "new" power CAC table, there is a relationship with the
table defining the link between vddc and the engine
clock. My tahiti based board does use the "old" cac table, but I
noticed the use of a virtual value (0xff??) for vddc in the vddc dependency
on engine clock table which is not translated to a real voltage
value.

This is found in si_dpm.c, si_get_std_voltage_value function.

Would that would explain why there are 2 lookup loops in
si_get_std_voltage_value function? (one looking for the exact
value, the other one seems to be a trick to deal with
untranslated virtual voltage).

regards,

-- 
Sylvain

Re: atombios powerplay cac table

[Sylvain BERTRAND]

On Thu, Nov 07, 2013 at 04:57:21AM +0100, Sylvain BERTRAND wrote:
> Which GPU generations/families do use the "new" powerplay CAC
> table, defined when the atombios platform capabilities have the
> ATOM_PP_PLATFORM_CAP_NEW_CAC_VOLTAGE flag?

I reply myself, since that was discussed on IRC, for archive.

agd5f said he does not know. Just care about the flag whatever
the generation/family is.

-- 
Sylvain