Re: [PATCH 00/30] drm/i915: Lots of workaround changes

Daniel Vetter
2013-07-05T20:13:32Z

On Fri, Jul 05, 2013 at 11:02:48PM +0300, Ville Syrjälä wrote:
> On Fri, Jul 05, 2013 at 12:51:54PM -0700, Ben Widawsky wrote:
> > On Fri, Jul 05, 2013 at 04:48:18PM +0300, ville.syrjala@linux.intel.com wrote:
> > > I was going over the workaround database with VLV mainly in mind, but I
> > > ended up stumbling on quite a few others as well.
> > >
> > > This series adds the workarounds names in a bunch of places where we
> > > missed them, adds a few workarounds we seem to have missed, drops some
> > > that were never supposed to be there, and drops quite a few pre-production
> > > workarounds.
> > >
> > > I'm not sure we want to drop some of the VLV workarounds quite yet. I know
> > > Jani will hate me when he comes back from vacation since his current machine
> > > would be affected.
> > >
> > > I've run these on my VLV and IVB machines, and didn't spot any problems.
> > > The SNB and HSW ones I've not actually tested.
> >
> > I have a sneaking suspicion at least a few of these will blow up once
> > their in the wild. You're trusting the docs an awful lot. At least the
> > patches seem quite bisectable though, so that's a saving grace.
>
> Yeah I wanted to keep them as isolated as possible just for that reason.
>
> > One thing which might be interesting/compelling is some performance data
> > (especially around places where you've removed unneeded workarounds).
>
> Some power consumption numbers migth be nice, since quite a few are
> clock gating related.
>
> There are plenty of options to deal with the risk:
> - Throw the patches away and pretend they never existed
> - Merge them all and watch out for fireworks
> - Drop a few of them into every kernel release to avoid too
> many regressions at once. I guess it'll take a few years
> get through the list this way.

Imo review them again, drop them into dinq, see what happens. If they blow
up we can yell at the Bsepc or w/a guys ;-)
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch