[Intel-gfx] [PATCH] drm/i915: Kill sink_crc for good

[Dhinakaran Pandiyan]

On Thu, 2018-07-05 at 14:25 -0700, Rodrigo Vivi wrote:
> On Thu, Jul 05, 2018 at 02:11:45PM -0700, Dhinakaran Pandiyan wrote:
> > 
> > On Thursday, July 5, 2018 12:25:28 PM PDT Rodrigo Vivi wrote:
> > > 
> > > It was originally introduced following the VESA spec in order to
> > > validate
> > > PSR.
> > > 
> > > However we found so many issues around sink_crc that instead of
> > > helping PSR
> > > development it only brought another layer of trouble to the
> > > table.
> > > 
> > > So, sink_crc has been a black whole for us in question of time,
> > > effort and
> > > hope.
> > > 
> > > First of the problems is that HW statement is clear: "Do not
> > > attempt to use
> > > aux communication with PSR enabled". So the main reason behind
> > > sink_crc is
> > > already compromised.
> > > 
> > > For a while we had hope on the aux-mutex could workaround this
> > > problem on
> > > SKL+ platforms, but that mutex was not reliable, not tested,
> > > and we shouldn't use according to HW engineers.
> > > 
> > > Also, nor source, nor sink designed and implemented the sink_crc
> > > to be used
> > > like we are trying to use here.
> > > 
> > > Well, the sink side of things is also apparently not prepared for
> > > this
> > > case. Each panel that we tried seemed to have a different
> > > behavior with same
> > > code and same source.
> > > 
> > > So, for all the time we lost on trying to ducktape all these
> > > different
> > > issues I believe it is now time to move PSR to a more reliable
> > > validation.
> > > Maybe not a perfect one as we dreamed for this sink_crc, but at
> > > least more
> > > reliable.
> > > 
> > Good riddance.
> Bye bye sink_crc, we are not going to miss you! ;)
> 
> > 
> > Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Thanks for granting me this honor!
> 
> now let's wait for CI to blow-up...
> than when we change psr test cases we come back here, trigger a
> retest and
> once CI is happy with push.

CI is indeed happy now.