[Intel-gfx] [PATCH 4/5] drm/i915: Assert that HSW/BDW LCPLL is using the non-SSC reference

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Only the non-SSC reference is truly supported for the LCPLL. Assert
that it is indeed selected.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display_power.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display_power.c b/drivers/gpu/drm/i915/intel_display_power.c
index 278a7edc94f5..bb9ef1cea5db 100644
--- a/drivers/gpu/drm/i915/intel_display_power.c
+++ b/drivers/gpu/drm/i915/intel_display_power.c
@@ -3665,6 +3665,9 @@ static void hsw_assert_cdclk(struct drm_i915_private *dev_priv)
 
 	if (val & LCPLL_PLL_DISABLE)
 		DRM_ERROR("LCPLL is disabled\n");
+
+	if ((val & LCPLL_REF_MASK) != LCPLL_REF_NON_SSC)
+		DRM_ERROR("LCPLL not using non-SSC reference\n");
 }
 
 static void assert_can_disable_lcpll(struct drm_i915_private *dev_priv)
-- 
2.21.0