From 12946eceeb97a36a7087995646e077e9872ac99b Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 27 Feb 2017 13:59:12 +0000 Subject: [PATCH] drm/i915: Remove redundant TLB invalidate on switching ppgtt We are required to reload the TLBs around ppgtt switches. However, we already do an unconditional TLB invalidate before every batch and a flush afterwards, so this condition is already satisfied without extra flushes around the LRI instructions. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/20170227135913.8056-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_gtt.c | 17 ----------------- 1 file changed, 17 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 875a48b..e0c9542 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1464,13 +1464,8 @@ static int hsw_mm_switch(struct i915_hw_ppgtt *ppgtt, { struct intel_engine_cs *engine = req->engine; u32 *cs; - int ret; /* NB: TLBs must be flushed and invalidated before a switch */ - ret = engine->emit_flush(req, EMIT_INVALIDATE | EMIT_FLUSH); - if (ret) - return ret; - cs = intel_ring_begin(req, 6); if (IS_ERR(cs)) return PTR_ERR(cs); @@ -1491,13 +1486,8 @@ static int gen7_mm_switch(struct i915_hw_ppgtt *ppgtt, { struct intel_engine_cs *engine = req->engine; u32 *cs; - int ret; /* NB: TLBs must be flushed and invalidated before a switch */ - ret = engine->emit_flush(req, EMIT_INVALIDATE | EMIT_FLUSH); - if (ret) - return ret; - cs = intel_ring_begin(req, 6); if (IS_ERR(cs)) return PTR_ERR(cs); @@ -1510,13 +1500,6 @@ static int gen7_mm_switch(struct i915_hw_ppgtt *ppgtt, *cs++ = MI_NOOP; intel_ring_advance(req, cs); - /* XXX: RCS is the only one to auto invalidate the TLBs? */ - if (engine->id != RCS) { - ret = engine->emit_flush(req, EMIT_INVALIDATE | EMIT_FLUSH); - if (ret) - return ret; - } - return 0; } -- 2.7.4