Comment 339 for bug 1690085

(In reply to Artem Hluvchynskyi from comment #252)
> I think both RCU workaround and disabling C6 (either through MSR or using
> the BIOS option) just masks the problem, which is probably on hardware
> level.

Maybe true.

[...]

> One thing I noticed is that with C6 disabled through the script or using the
> "Typical Current" power supply option in BIOS in my case MB sensors never
> report Vcore less than 0.8V, which indicates that indeed it doesn't reach
> lower idle states even if only "package C6" is disabled. On default settings
> it will frequently report 0.4-0.5V range when idle.

I'm reaching exactly this 0.4-0.5V range with overclocking (+200 MHz) and C6 completely enabled - and I didn't see the problem any more since a lot of weeks now (before not even after an hour). My PSU officially is definitely not C6/C7 capable because it's too old.

> Since Zen would only apply boosting and especially XFR when certain power
> and thermal conditions are met, disabling the deep idle states may affect
> this adversely. So IMO all that should be well tested before applying a
> workaround like this on the kernel level.

Fine with me if its switchable (opt in).

Nevertheless it would be indisputable much better to have a real fix basing of the real reason instead of a workaround - but I fear it won't come anytime soon.