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From 0a46ddd57c9ef9fb5376d4bff65d07e0aea30f35 Mon Sep 17 00:00:00 2001
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Wed, 30 Aug 2017 21:52:23 -0700
Subject: [PATCH] drm/i915/cnp: Wa 1181: Fix Backlight issue
Git-commit: 0a46ddd57c9ef9fb5376d4bff65d07e0aea30f35
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900

This workaround fixes a CNL PCH bug when changing
backlight from a lower frequency to a higher frequency.

During random reboot cycles, display backlight seems to
be off/ dim for 2-3 mins.

The only functional change on this patch is to
set bit 13 of 0xC2020 for CNL PCH.

The rest of patch is organizing identation around
those bits definitions and re-organizing CFL workarounds.

V2: Only add the bit that matters without touching others    around (Jani).    Rebase on top of clock gating functions rename.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Arthur J Runyan <arthur.j.runyan@intel.com>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170831045223.3960-1-rodrigo.vivi@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_reg.h |    1 +
 drivers/gpu/drm/i915/intel_pm.c |   27 +++++++++++++++++++++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7484,6 +7484,7 @@ enum {
 #define  PCH_DPLUNIT_CLOCK_GATE_DISABLE (1<<30)
 #define  PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29)
 #define  PCH_CPUNIT_CLOCK_GATE_DISABLE (1<<14)
+#define  CNP_PWM_CGE_GATING_DISABLE (1<<13)
 #define  PCH_LP_PARTITION_LEVEL_DISABLE  (1<<12)
 
 /* CPU: FDI_TX */
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -8258,8 +8258,19 @@ static void gen8_set_l3sqc_credits(struc
 	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
 }
 
+static void cnp_init_clock_gating(struct drm_i915_private *dev_priv)
+{
+	if (!HAS_PCH_CNP(dev_priv))
+		return;
+
+	/* Wa #1181 */
+	I915_WRITE(SOUTH_DSPCLK_GATE_D, CNP_PWM_CGE_GATING_DISABLE);
+}
+
 static void cnl_init_clock_gating(struct drm_i915_private *dev_priv)
 {
+	cnp_init_clock_gating(dev_priv);
+
 	/* This is not an Wa. Enable for better image quality */
 	I915_WRITE(_3D_CHICKEN3,
 		   _MASKED_BIT_ENABLE(_3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE));
@@ -8279,6 +8290,16 @@ static void cnl_init_clock_gating(struct
 			   SARBUNIT_CLKGATE_DIS);
 }
 
+static void cfl_init_clock_gating(struct drm_i915_private *dev_priv)
+{
+	cnp_init_clock_gating(dev_priv);
+	gen9_init_clock_gating(dev_priv);
+
+	/* WaFbcNukeOnHostModify:cfl */
+	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
+		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
+}
+
 static void kbl_init_clock_gating(struct drm_i915_private *dev_priv)
 {
 	gen9_init_clock_gating(dev_priv);
@@ -8293,7 +8314,7 @@ static void kbl_init_clock_gating(struct
 		I915_WRITE(GEN6_UCGCTL1, I915_READ(GEN6_UCGCTL1) |
 			   GEN6_GAMUNIT_CLOCK_GATE_DISABLE);
 
-	/* WaFbcNukeOnHostModify:kbl,cfl */
+	/* WaFbcNukeOnHostModify:kbl */
 	I915_WRITE(ILK_DPFC_CHICKEN, I915_READ(ILK_DPFC_CHICKEN) |
 		   ILK_DPFC_NUKE_ON_ANY_MODIFICATION);
 }
@@ -8761,9 +8782,11 @@ void intel_init_clock_gating_hooks(struc
 {
 	if (IS_CANNONLAKE(dev_priv))
 		dev_priv->display.init_clock_gating = cnl_init_clock_gating;
+	else if (IS_COFFEELAKE(dev_priv))
+		dev_priv->display.init_clock_gating = cfl_init_clock_gating;
 	else if (IS_SKYLAKE(dev_priv))
 		dev_priv->display.init_clock_gating = skl_init_clock_gating;
-	else if (IS_KABYLAKE(dev_priv) || IS_COFFEELAKE(dev_priv))
+	else if (IS_KABYLAKE(dev_priv))
 		dev_priv->display.init_clock_gating = kbl_init_clock_gating;
 	else if (IS_BROXTON(dev_priv))
 		dev_priv->display.init_clock_gating = bxt_init_clock_gating;