[Intel-gfx] [PATCH 1/2] drm/i915: POSTING_READ IPS_CTL before waiting for the vblank

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

Make sure we write to IPS before we actually wait.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index fc55570..78ff5ed 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);
-- 
1.8.3.1