From e37ec39b180c53dea3106ceb8f247bcba47dfb82 Mon Sep 17 00:00:00 2001 From: Ben Widawsky Date: Mon, 4 Jun 2012 14:42:48 -0700 Subject: [PATCH] drm/i915: Ivybridge MI_ARB_ON_OFF context w/a The workaround itself applies to gen7 only (according to the docs) and as Eric Anholt points out shouldn't be required since we don't use HW scheduling features, and therefore arbitration. Though since it is a small, and simple addition, and we don't really understand the issue, just do it. FWIW, I eventually want to play with some of the arbitration stuff, and I'd hate to forget about this. Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_gem_context.c | 12 +++++++++++- drivers/gpu/drm/i915/i915_reg.h | 3 +++ 2 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index fb6aa5e10991..d49d5fc0a592 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -324,10 +324,15 @@ mi_set_context(struct intel_ring_buffer *ring, { int ret; - ret = intel_ring_begin(ring, 4); + ret = intel_ring_begin(ring, 6); if (ret) return ret; + if (IS_GEN7(ring->dev)) + intel_ring_emit(ring, MI_ARB_ON_OFF | MI_ARB_DISABLE); + else + intel_ring_emit(ring, MI_NOOP); + intel_ring_emit(ring, MI_NOOP); intel_ring_emit(ring, MI_SET_CONTEXT); intel_ring_emit(ring, new_context->obj->gtt_offset | @@ -338,6 +343,11 @@ mi_set_context(struct intel_ring_buffer *ring, /* w/a: MI_SET_CONTEXT must always be followed by MI_NOOP */ intel_ring_emit(ring, MI_NOOP); + if (IS_GEN7(ring->dev)) + intel_ring_emit(ring, MI_ARB_ON_OFF | MI_ARB_ENABLE); + else + intel_ring_emit(ring, MI_NOOP); + intel_ring_advance(ring); return ret; diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index bee101208195..14cb714df352 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -210,6 +210,9 @@ #define MI_DISPLAY_FLIP MI_INSTR(0x14, 2) #define MI_DISPLAY_FLIP_I915 MI_INSTR(0x14, 1) #define MI_DISPLAY_FLIP_PLANE(n) ((n) << 20) +#define MI_ARB_ON_OFF MI_INSTR(0x08, 0) +#define MI_ARB_ENABLE (1<<0) +#define MI_ARB_DISABLE (0<<0) #define MI_SET_CONTEXT MI_INSTR(0x18, 0) #define MI_MM_SPACE_GTT (1<<8) #define MI_MM_SPACE_PHYSICAL (0<<8)