[PATCH 3.11 022/233] drm/i915: fix DDI PLLs HW state readout code

[Luis Henriques <luis.henriques@canonical.com>]

3.11.10.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

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

commit 0882dae983707455e97479e5e904e37673517ebc upstream.

Properly zero the refcounts and crtc->ddi_pll_set so the previous HW
state doesn't affect the result of reading the current HW state.

This fixes WARNs about WRPLL refcount if we have an HDMI monitor on
HSW and then suspend/resume.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64379
Tested-by: Qingshuai Tian <qingshuai.tian@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/gpu/drm/i915/intel_ddi.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index e9af22a..029a165 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -978,12 +978,18 @@ void intel_ddi_setup_hw_pll_state(struct drm_device *dev)
 	enum pipe pipe;
 	struct intel_crtc *intel_crtc;
 
+	dev_priv->ddi_plls.spll_refcount = 0;
+	dev_priv->ddi_plls.wrpll1_refcount = 0;
+	dev_priv->ddi_plls.wrpll2_refcount = 0;
+
 	for_each_pipe(pipe) {
 		intel_crtc =
 			to_intel_crtc(dev_priv->pipe_to_crtc_mapping[pipe]);
 
-		if (!intel_crtc->active)
+		if (!intel_crtc->active) {
+			intel_crtc->ddi_pll_sel = PORT_CLK_SEL_NONE;
 			continue;
+		}
 
 		intel_crtc->ddi_pll_sel = intel_ddi_get_crtc_pll(dev_priv,
 								 pipe);
-- 
1.8.3.2