From: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Tue, 15 Nov 2011 18:28:53 +0000 (-0800)
Subject: drm/i915: don't disable a PCH DPLL that's in use
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7a4198664d46b87025a64530f1530ab2bea54c19;p=linux-beck.git

drm/i915: don't disable a PCH DPLL that's in use

If a PCH pipe PLL is being used by transcoder C, don't disable it.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2e00c8ae361c..bdab82b999e0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1204,7 +1204,8 @@ static void intel_disable_pch_pll(struct drm_i915_private *dev_priv,
 				  enum pipe pipe)
 {
 	int reg;
-	u32 val;
+	u32 val, pll_mask = TRANSC_DPLL_ENABLE | TRANSC_DPLLB_SEL,
+		pll_sel = TRANSC_DPLL_ENABLE;
 
 	if (pipe > 1)
 		return;
@@ -1215,6 +1216,15 @@ static void intel_disable_pch_pll(struct drm_i915_private *dev_priv,
 	/* Make sure transcoder isn't still depending on us */
 	assert_transcoder_disabled(dev_priv, pipe);
 
+	if (pipe == 0)
+		pll_sel |= TRANSC_DPLLA_SEL;
+	else if (pipe == 1)
+		pll_sel |= TRANSC_DPLLB_SEL;
+
+
+	if ((I915_READ(PCH_DPLL_SEL) & pll_mask) == pll_sel)
+		return;
+
 	reg = PCH_DPLL(pipe);
 	val = I915_READ(reg);
 	val &= ~DPLL_VCO_ENABLE;