From: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date: Thu, 19 Sep 2013 20:03:05 +0000 (-0300)
Subject: drm/i915: POSTING_READ IPS_CTL before waiting for the vblank
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=81c12f6e78c535533e9258bd9476b5d7419d3cce;p=openwrt%2Fstaging%2Fblogic.git

drm/i915: POSTING_READ IPS_CTL before waiting for the vblank

Make sure we write to IPS before we actually wait.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2ed974e1d08b..1a4232e446fe 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3386,6 +3386,7 @@ static void hsw_disable_ips(struct intel_crtc *crtc)
 
 	assert_plane_enabled(dev_priv, crtc->plane);
 	I915_WRITE(IPS_CTL, 0);
+	POSTING_READ(IPS_CTL);
 
 	/* We need to wait for a vblank before we can disable the plane. */
 	intel_wait_for_vblank(dev, crtc->pipe);