From 54ec12af2fb8ee761b092fabbf6e135648d23041 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 18 Mar 2017 10:42:57 +0000 Subject: [PATCH] drm/i915: Skip force-wake for uncached mmio flush of GGTT writes The trick of using an uncached mmio read to ensure that the GGTT writes are flushed does not require us to do the forcewake dance, so avoid it in the hope of reducing the frequency that we do keep the device forced awake. Signed-off-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/20170318104257.694-1-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_gem.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 58e1db77d70e..bb65072f688d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -3307,8 +3307,11 @@ i915_gem_object_flush_gtt_write_domain(struct drm_i915_gem_object *obj) * system agents we cannot reproduce this behaviour). */ wmb(); - if (INTEL_GEN(dev_priv) >= 6 && !HAS_LLC(dev_priv)) - POSTING_READ(RING_ACTHD(dev_priv->engine[RCS]->mmio_base)); + if (INTEL_GEN(dev_priv) >= 6 && !HAS_LLC(dev_priv)) { + spin_lock_irq(&dev_priv->uncore.lock); + POSTING_READ_FW(RING_ACTHD(dev_priv->engine[RCS]->mmio_base)); + spin_unlock_irq(&dev_priv->uncore.lock); + } intel_fb_obj_flush(obj, write_origin(obj, I915_GEM_DOMAIN_GTT)); -- 2.11.0