Quoting Mika Kuoppala (2019-09-10 10:54:43) > Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > > > Quoting Mika Kuoppala (2019-09-10 10:31:05) > >> Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes: > >> > >> > During reset, we try to ensure no forward progress of the CS prior to > >> > the reset by setting the STOP_RING bit in RING_MI_MODE. Since gen9, this > >> > register is context saved and do we end up in the odd situation where we > >> > save the STOP_RING bit and so try to stop the engine again immediately > >> > upon resume. This is quite unexpected and causes us to complain about an > >> > early CS completion event! > >> > >> The completion event is a product of resume with a stop set? > > > > A completion event is the product of STOP_RING. Whether it is the > > completion event that we keep failing on... > > > >> If my memory serves me well, we have fought this before. > > > > Exactly. We've reduced the frequency of when we apply the STOP_RING, but > > have not eliminated it. > > > >> But I have still missing pieces. Why would we not want to > >> set this for all contexts primed for execution? In gen8 too. > > > > It's not in the gen8 context, afaict. I searched the context image for an > > LRI with the RING_MI_MODE register: > > https://patchwork.freedesktop.org/patch/329919/?series=66468&rev=1 > > > >> I mean, queuing context with a ring stopped just doesn't > >> sound right on any gen. > > > > We clear the STOP_RING in the register on resume just in case, and that > > is being flagged on Icelake (which I put down to the reset not being very > > thorough!). The remaining question was whether we were restoring it from > > the context image. > > Hmm yeah, I was confused of the sequence of setup. With that cleared > and with the context state being worked on, perhaps we can add > sanity checkers to the queuing path. Yeah, I think there's definitely some fun we can have here. At the very least a check that CTX_RING_START == ring->start would be a good sanitycheck. > Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx> As always, the only way to be sure if this changes the mtbf is to let is soak. One day I may be able to run my own extended testing on icl! -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
