From d7619c4b9c95cc9a2e7f0f4f7ae21165ab5cb1e7 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 11 Feb 2009 14:26:47 +0000 Subject: [PATCH] drm/i915: Protect active fences on i915 The i915 also uses the fence registers for GPU access to tiled buffers so we cannot reallocate one whilst it is on the active list. By performing a LRU scan of the fenced buffers we also avoid waiting the possibility of waiting on a pinned, or otherwise unusable, buffer. Signed-off-by: Chris Wilson Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/i915_gem.c | 38 +++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 2b5c7ad9e64..b0ff5c44e61 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1595,18 +1595,32 @@ try_again: /* None available, try to steal one or wait for a user to finish */ if (i == dev_priv->num_fence_regs) { + uint32_t seqno = dev_priv->mm.next_gem_seqno; loff_t offset; if (avail == 0) return -ENOMEM; - /* Could try to use LRU here instead... */ for (i = dev_priv->fence_reg_start; i < dev_priv->num_fence_regs; i++) { + uint32_t this_seqno; + reg = &dev_priv->fence_regs[i]; old_obj_priv = reg->obj->driver_private; - if (!old_obj_priv->pin_count) + + if (old_obj_priv->pin_count) + continue; + + /* i915 uses fences for GPU access to tiled buffers */ + if (IS_I965G(dev) || !old_obj_priv->active) break; + + /* find the seqno of the first available fence */ + this_seqno = old_obj_priv->last_rendering_seqno; + if (this_seqno != 0 && + reg->obj->write_domain == 0 && + i915_seqno_passed(seqno, this_seqno)) + seqno = this_seqno; } /* @@ -1614,15 +1628,25 @@ try_again: * objects to finish before trying again. */ if (i == dev_priv->num_fence_regs) { - ret = i915_gem_object_set_to_gtt_domain(reg->obj, 0); - if (ret) { - WARN(ret != -ERESTARTSYS, - "switch to GTT domain failed: %d\n", ret); - return ret; + if (seqno == dev_priv->mm.next_gem_seqno) { + i915_gem_flush(dev, + I915_GEM_GPU_DOMAINS, + I915_GEM_GPU_DOMAINS); + seqno = i915_add_request(dev, + I915_GEM_GPU_DOMAINS); + if (seqno == 0) + return -ENOMEM; } + + ret = i915_wait_request(dev, seqno); + if (ret) + return ret; goto try_again; } + BUG_ON(old_obj_priv->active || + (reg->obj->write_domain & I915_GEM_GPU_DOMAINS)); + /* * Zap this virtual mapping so we can set up a fence again * for this object next time we need it. -- 2.41.1