Chris Wilson <chris at chris-wilson.co.uk> writes: > On Tue, 18 Dec 2012 19:26:18 +0200, Mika Kuoppala <mika.kuoppala at linux.intel.com> wrote: >> Hardware status page needs to have proper seqno set >> as our initial seqno can be arbitrary. If initial seqno is close >> to wrap boundary on init and i915_seqno_passed() (31bit space) >> refers to hw status page which contains zero, errorneous result >> will be returned. >> >> v2: clear mboxes and set hws page directly instead of going >> through rings. Suggested by Chris Wilson. >> >> v3: hws needs to be updated for all gens. Noticed by Chris >> Wilson. >> >> References: https://bugs.freedesktop.org/show_bug.cgi?id=58230 >> Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com> > >> -int intel_ring_handle_seqno_wrap(struct intel_ring_buffer *ring) >> +void intel_ring_init_seqno(struct intel_ring_buffer *ring, u32 seqno) >> { >> - int ret; >> + struct drm_i915_private *dev_priv = ring->dev->dev_private; >> >> BUG_ON(ring->outstanding_lazy_request); >> >> - if (INTEL_INFO(ring->dev)->gen < 6) >> - return 0; >> - >> - ret = __intel_ring_begin(ring, 6 * sizeof(uint32_t)); >> - if (ret) >> - return ret; >> - >> - /* Leaving a stale, pre-wrap seqno behind in the mboxes will result in >> - * post-wrap semaphore waits completing immediately. Clear them. */ >> - update_mboxes(ring, ring->signal_mbox[0]); >> - update_mboxes(ring, ring->signal_mbox[1]); >> - intel_ring_advance(ring); >> + if (INTEL_INFO(ring->dev)->gen >= 6) { >> + I915_WRITE(RING_SYNC_0(ring->mmio_base), 0); >> + I915_WRITE(RING_SYNC_1(ring->mmio_base), 0); >> + } >> >> - return 0; >> + intel_write_status_page(ring, I915_GEM_HWS_INDEX, seqno); > > There's yet another complication here: not all gen use the HWS. Ironlake > uses a pipecontrol write to another page -- though in principle we could > write to the HWS instead. > I posted a new series which adds ring::set_seqno to take care per architecture seqno writing... > Any one feel like that challenge? ... and i will rip the ring:set_seqno out when ilk uses hws. -Mika > -Chris > > -- > Chris Wilson, Intel Open Source Technology Centre
