drm/i915: Move init_clock_gating() back to where it was

Apparently setting up a bunch of GT registers before we've properly
initialized the rest of the GT hardware leads to these setting being
lost. So looks like I broke HSW with commit b7048ea12fbb ("drm/i915:
Do .init_clock_gating() earlier to avoid it clobbering watermarks")
by doing init_clock_gating() too early. This should actually affect
other platforms as well, but apparently not to such a great degree.

What I was ultimately after in that commit was to move the
ilk_init_lp_watermarks() call earlier. So let's undo the damage and
move init_clock_gating() back to where it was, and call
ilk_init_lp_watermarks() just before the watermark state readout.

This highlights how fragile and messed up our init order really is.
I wonder why we even initialize the display before gem. The opposite
order would make much more sense to me...

v2: Keep WaRsPkgCStateDisplayPMReq:hsw early as it really must
    be done before all planes might get disabled.

Cc: stable@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mark Janes <mark.a.janes@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Oscar Mateo <oscar.mateo@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reported-by: Mark Janes <mark.a.janes@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103549
Fixes: b7048ea12fbb ("drm/i915: Do .init_clock_gating() earlier to avoid it clobbering watermarks")
References: https://lists.freedesktop.org/archives/intel-gfx/2017-November/145432.html
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171108133555.14091-1-ville.syrjala@linux.intel.com
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3dec70fa1ee8..84817ccc5305 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3674,6 +3674,7 @@ void intel_finish_reset(struct drm_i915_private *dev_priv)
 
 		intel_pps_unlock_regs_wa(dev_priv);
 		intel_modeset_init_hw(dev);
+		intel_init_clock_gating(dev_priv);
 
 		spin_lock_irq(&dev_priv->irq_lock);
 		if (dev_priv->display.hpd_irq_setup)
@@ -14363,8 +14364,6 @@ void intel_modeset_init_hw(struct drm_device *dev)
 	intel_update_cdclk(dev_priv);
 	intel_dump_cdclk_state(&dev_priv->cdclk.hw, "Current CDCLK");
 	dev_priv->cdclk.logical = dev_priv->cdclk.actual = dev_priv->cdclk.hw;
-
-	intel_init_clock_gating(dev_priv);
 }
 
 /*
@@ -15094,6 +15093,15 @@ intel_modeset_setup_hw_state(struct drm_device *dev,
 	struct intel_encoder *encoder;
 	int i;
 
+	if (IS_HASWELL(dev_priv)) {
+		/*
+		 * WaRsPkgCStateDisplayPMReq:hsw
+		 * System hang if this isn't done before disabling all planes!
+		 */
+		I915_WRITE(CHICKEN_PAR1_1,
+			   I915_READ(CHICKEN_PAR1_1) | FORCE_ARB_IDLE_PLANES);
+	}
+
 	intel_modeset_readout_hw_state(dev);
 
 	/* HW state is read out, now we need to sanitize this mess. */
@@ -15191,6 +15199,8 @@ void intel_modeset_gem_init(struct drm_device *dev)
 
 	intel_init_gt_powersave(dev_priv);
 
+	intel_init_clock_gating(dev_priv);
+
 	intel_setup_overlay(dev_priv);
 }