Extract all this logic into a new helper function semaphore_wait_to_signaller_ring because:
- The current code has way too much magic. - The current code doesn't look at bi16, which encodes VECS signallers on HSW. Those are just added after the fact, so can't be encoded in a neat formula. - It blindly trust the hardware for the dev_priv->ring array derefence, which given that we have a gpu hang at hand is scary. The current logic can't blow up since it limits its value range sufficiently, but that's a bit too tricky to rely on in my opinion. Especially when we start to add bdw support. - I'm not a big fan of the explicit ring->semaphore_register list, but I think it's more robust to use the same mapping both when constructing the semaphore commands and when decoding them. - Finally add a FIXME comment about lack of broadwell support here, like in the earlier ipehr semaphore cmd detection function. Cc: Mika Kuoppala <[email protected]> Cc: Ben Widawsky <[email protected]> Cc: Chris Wilson <[email protected]> Signed-off-by: Daniel Vetter <[email protected]> --- drivers/gpu/drm/i915/i915_irq.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 0f3a6d791502..98f95ca77246 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2543,6 +2543,39 @@ ipehr_is_semaphore_wait(struct drm_device *dev, u32 ipehr) } static struct intel_ring_buffer * +semaphore_wait_to_signaller_ring(struct intel_ring_buffer *ring, u32 ipehr) +{ + struct drm_i915_private *dev_priv = ring->dev->dev_private; + struct intel_ring_buffer *signaller; + int i; + + if (INTEL_INFO(dev_priv->dev)->gen >= 8) { + /* + * FIXME: gen8 semaphore support - currently we don't emit + * semaphores on bdw anyway, but this needs to be addressed when + * we merge that code. + */ + return NULL; + } else { + u32 sync_bits = ipehr & MI_SEMAPHORE_SYNC_MASK; + + for_each_ring(signaller, dev_priv, i) { + if(ring == signaller) + continue; + + if (sync_bits == + signaller->semaphore_register[ring->id]) + return signaller; + } + } + + DRM_ERROR("No signaller ring found for ring %i, ipehr 0x%08x\n", + ring->id, ipehr); + + return NULL; +} + +static struct intel_ring_buffer * semaphore_waits_for(struct intel_ring_buffer *ring, u32 *seqno) { struct drm_i915_private *dev_priv = ring->dev->dev_private; @@ -2582,7 +2615,7 @@ semaphore_waits_for(struct intel_ring_buffer *ring, u32 *seqno) return NULL; *seqno = ioread32(ring->virtual_start + head + 4) + 1; - return &dev_priv->ring[(ring->id + (((ipehr >> 17) & 1) + 1)) % 3]; + return semaphore_wait_to_signaller_ring(ring, ipehr); } static int semaphore_passed(struct intel_ring_buffer *ring) -- 1.8.1.4 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
