From: Chris Wilson Date: Sat, 18 Mar 2017 10:42:57 +0000 (+0000) Subject: drm/i915: Skip force-wake for uncached mmio flush of GGTT writes X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=54ec12af2fb8ee761b092fabbf6e135648d23041;p=openwrt%2Fstaging%2Fblogic.git 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 --- 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));