<div class="gmail_quote">On Sun, Feb 12, 2012 at 18:10, Keith Packard <span dir="ltr"><<a href="mailto:keithp@keithp.com">keithp@keithp.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div class="im">On Sat, 11 Feb 2012 17:24:16 -0200, Eugeni Dodonov <<a href="mailto:eugeni@dodonov.net">eugeni@dodonov.net</a>> wrote:<br>
<br>
> So far I had 2 reports saying that RC6 solved the problems which were<br>
> present with RC6+RC6p (previous default) on SNB.<br>
<br>
</div>For -fixes, I think we shouldn't enable rc6 by default, but we may want<br>
to change what enabling rc6 does on SNB to stop using deeper states?<br>
That should let more people enable it manually at least.<br></blockquote><div><br>Hi Keith,<br><br>what if we pick only the 1st patch in this series for -fixes? It won't change the defaults in any way, but it will allow the ones willing to enable it manually on SNB to prevent issues.<br>
<br>E.g., with this patch, passing i915_enable_rc6=1 will enable plain RC6, and leave deep RC6 off. This is probably the safest setting so far - it results in nice power savings and all the other benefits of RC6, but avoid entering RC6+ - which seems to be responsible for all the issues on the affected machines apparently. And it would further help to isolate which rc6 states are the guilty ones on the affected machines, so in case any other problem arises, we can ask people to test with different 'i915_enable_rc6=N' parameter prior to fully reverting it again..<br>
<br>The change of the default value for SNB could go into -next kernel. By the time we'll get to the first release of 3.4 we'll certainly know if there are any issues with that.<br clear="all"></div></div><br>-- <br>
Eugeni Dodonov<a href="http://eugeni.dodonov.net/" target="_blank"><br></a><br>