From 14d8ec544f2351a5da33e233b75f44cf6a5bea8e Mon Sep 17 00:00:00 2001 From: Oscar Mateo Date: Wed, 18 Jun 2014 17:16:03 +0100 Subject: [PATCH] drm/i915: Remove ctx->last_ring The original comment that introduced it said: commit 0009e46cd54324c4af20b0b52b89973b1b914167 Author: Ben Widawsky Date: Fri Dec 6 14:11:02 2013 -0800 drm/i915: Track which ring a context ran on Previously we dropped the association of a context to a ring. It is however very important to know which ring a context ran on (we could have reused the other member, but I was nitpicky). This is very important when we switch address spaces, which unlike context objects, do change per ring. As an example, if we have: RCS BCS ctx A ctx A ctx B ctx B Without tracking the last ring B ran on, we wouldn't know to switch the address space on BCS in the last row. But this is not really true, because we are already checking to != from (with "from" being = ring->last_context) and that should be enough to make sure we switch to the right address space. We would have a problem if we switched the context object for every ring (since then we would fail to do it in some situations) but we only switch it for the render ring, so we don't care. Signed-off-by: Oscar Mateo Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 1 - drivers/gpu/drm/i915/i915_gem_context.c | 3 +-- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 0640071e30a9..4fea8a07a85e 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -591,7 +591,6 @@ struct intel_context { bool is_initialized; uint8_t remap_slice; struct drm_i915_file_private *file_priv; - struct intel_engine_cs *last_ring; struct drm_i915_gem_object *obj; struct i915_ctx_hang_stats hang_stats; struct i915_address_space *vm; diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 3ffe308d5893..21eda88ff541 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -605,7 +605,7 @@ static int do_switch(struct intel_engine_cs *ring, BUG_ON(!i915_gem_obj_is_pinned(from->obj)); } - if (from == to && from->last_ring == ring && !to->remap_slice) + if (from == to && !to->remap_slice) return 0; /* Trying to pin first makes error handling easier. */ @@ -699,7 +699,6 @@ static int do_switch(struct intel_engine_cs *ring, done: i915_gem_context_reference(to); ring->last_context = to; - to->last_ring = ring; if (ring->id == RCS && !to->is_initialized && from == NULL) { ret = i915_gem_render_state_init(ring);