drm/i915: Fix PCH PLL assertions to not assume CRTC:PLL relationship

The existing assertions were written under the assumption that we wanted
to test the related PLL to a CRTC. With the split of PLL into a
separately managed entity which may be shared amongst CRTCs, we need to
pass in both the CRTC and the PLL to the assertion routine.
Occassionally, this means passing NULL for the CRTC as we wish to check
the status of the PLL irrespective of the current CRTC.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -910,9 +910,10 @@ static void assert_pll(struct drm_i915_private *dev_priv,
 
 /* For ILK+ */
 static void assert_pch_pll(struct drm_i915_private *dev_priv,
-			   struct intel_crtc *intel_crtc, bool state)
+			   struct intel_pch_pll *pll,
+			   struct intel_crtc *crtc,
+			   bool state)
 {
-	int reg;
 	u32 val;
 	bool cur_state;
 
@@ -921,30 +922,37 @@ static void assert_pch_pll(struct drm_i915_private *dev_priv,
 		return;
 	}
 
-	if (!intel_crtc->pch_pll) {
-		WARN(1, "asserting PCH PLL enabled with no PLL\n");
+	if (WARN (!pll,
+		  "asserting PCH PLL %s with no PLL\n", state_string(state)))
 		return;
-	}
 
-	if (HAS_PCH_CPT(dev_priv->dev)) {
+	val = I915_READ(pll->pll_reg);
+	cur_state = !!(val & DPLL_VCO_ENABLE);
+	WARN(cur_state != state,
+	     "PCH PLL state for reg %x assertion failure (expected %s, current %s), val=%08x\n",
+	     pll->pll_reg, state_string(state), state_string(cur_state), val);
+
+	/* Make sure the selected PLL is correctly attached to the transcoder */
+	if (crtc && HAS_PCH_CPT(dev_priv->dev)) {
 		u32 pch_dpll;
 
 		pch_dpll = I915_READ(PCH_DPLL_SEL);
-
-		/* Make sure the selected PLL is enabled to the transcoder */
-		WARN(!((pch_dpll >> (4 * intel_crtc->pipe)) & 8),
-		     "transcoder %d PLL not enabled\n", intel_crtc->pipe);
-	}
-
-	reg = intel_crtc->pch_pll->pll_reg;
-	val = I915_READ(reg);
-	cur_state = !!(val & DPLL_VCO_ENABLE);
+		cur_state = pll->pll_reg == _PCH_DPLL_B;
+		if (!WARN(((pch_dpll >> (4 * crtc->pipe)) & 1) != cur_state,
+			  "PLL[%d] not attached to this transcoder %d: %08x\n",
+			  cur_state, crtc->pipe, pch_dpll)) {
+			cur_state = !!(val >> (4*crtc->pipe + 3));
 			WARN(cur_state != state,
-	     "PCH PLL state assertion failure (expected %s, current %s)\n",
-	     state_string(state), state_string(cur_state));
+			     "PLL[%d] not %s on this transcoder %d: %08x\n",
+			     pll->pll_reg == _PCH_DPLL_B,
+			     state_string(state),
+			     crtc->pipe,
+			     val);
+		}
+	}
 }
-#define assert_pch_pll_enabled(d, p) assert_pch_pll(d, p, true)
-#define assert_pch_pll_disabled(d, p) assert_pch_pll(d, p, false)
+#define assert_pch_pll_enabled(d, p, c) assert_pch_pll(d, p, c, true)
+#define assert_pch_pll_disabled(d, p, c) assert_pch_pll(d, p, c, false)
 
 static void assert_fdi_tx(struct drm_i915_private *dev_priv,
 			  enum pipe pipe, bool state)
@@ -1424,7 +1432,7 @@ static void intel_enable_pch_pll(struct intel_crtc *intel_crtc)
 	assert_pch_refclk_enabled(dev_priv);
 
 	if (pll->active++ && pll->on) {
-		assert_pch_pll_enabled(dev_priv, intel_crtc);
+		assert_pch_pll_enabled(dev_priv, pll, NULL);
 		return;
 	}
 
@@ -1460,12 +1468,12 @@ static void intel_disable_pch_pll(struct intel_crtc *intel_crtc)
 		      intel_crtc->base.base.id);
 
 	if (WARN_ON(pll->active == 0)) {
-		assert_pch_pll_disabled(dev_priv, intel_crtc);
+		assert_pch_pll_disabled(dev_priv, pll, NULL);
 		return;
 	}
 
 	if (--pll->active) {
-		assert_pch_pll_enabled(dev_priv, intel_crtc);
+		assert_pch_pll_enabled(dev_priv, pll, NULL);
 		return;
 	}
 
@@ -1495,7 +1503,9 @@ static void intel_enable_transcoder(struct drm_i915_private *dev_priv,
 	BUG_ON(dev_priv->info->gen < 5);
 
 	/* Make sure PCH DPLL is enabled */
-	assert_pch_pll_enabled(dev_priv, to_intel_crtc(crtc));
+	assert_pch_pll_enabled(dev_priv,
+			       to_intel_crtc(crtc)->pch_pll,
+			       to_intel_crtc(crtc));
 
 	/* FDI must be feeding us bits for PCH ports */
 	assert_fdi_tx_enabled(dev_priv, pipe);