[Intel-gfx] [PATCH 0/1] i915: pm: Be less agressive with clockfreq changes on Bay Trail

[Hans de Goede]

Hi All,

So this patch, which I already submitted a while ago and back then it
got one comment from Chris Wilson:

> Basically you want a limit on the frequency of ... pcode access?
> As presented, you ultimately do not trust any write and the only
> solution is to disable all writes. No RPS whatsoever, run at max and
> hope rc6 works (maybe even decrease the rc6 threshold).
> 
> One of the ideas we floated was moving the pcode access to a worker and
> ratelimiting the updates.

Has finally seen some testing by users affected by the infamous
"intel_idle.max_cstate=1 required to prevent crashes" bug:
https://bugzilla.kernel.org/show_bug.cgi?id=109051

And so far the reports are that it does help to make the users stable for
2/3 users and it not being effective for 1/3 users.

Now that we've some test results,  I believe that it is worthwhile to get
this simple patch mainlined, hence this re-submission.

Regards,

Hans