[PATCH 2/2] drm/i915: preserve user forcewake over system suspend/resume

[Imre Deak <imre.deak@intel.com>]

Atm, the forcewake refcount will be incorrectly set to zero during
system suspend if there is any reference held via the
i915_forcewake_user debugfs entry.

Fix this by simply not zeroing the sw counters during suspend and
restoring the original state using them. Note that the only other
places where we zeroed the counters were driver load and unload time,
where it was redundant anyway.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78059
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c     |  2 +-
 drivers/gpu/drm/i915/i915_drv.h     |  3 ++-
 drivers/gpu/drm/i915/intel_uncore.c | 10 +++-------
 3 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 615b62f..5a08c86 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -600,7 +600,7 @@ static int i915_drm_thaw_early(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	intel_uncore_early_sanitize(dev);
+	intel_uncore_early_sanitize(dev, true);
 	intel_uncore_sanitize(dev);
 	intel_power_domains_init_hw(dev_priv);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 8631fb3..e79f7bb 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2078,7 +2078,8 @@ extern void intel_irq_init(struct drm_device *dev);
 extern void intel_hpd_init(struct drm_device *dev);
 
 extern void intel_uncore_sanitize(struct drm_device *dev);
-extern void intel_uncore_early_sanitize(struct drm_device *dev);
+extern void intel_uncore_early_sanitize(struct drm_device *dev,
+					bool restore_forcewake);
 extern void intel_uncore_init(struct drm_device *dev);
 extern void intel_uncore_check_errors(struct drm_device *dev);
 extern void intel_uncore_fini(struct drm_device *dev);
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 389e235..14ae557 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -364,16 +364,12 @@ static void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
 			dev_priv->uncore.fifo_count =
 				__raw_i915_read32(dev_priv, GTFIFOCTL) &
 				GT_FIFO_FREE_ENTRIES_MASK;
-	} else {
-		dev_priv->uncore.forcewake_count = 0;
-		dev_priv->uncore.fw_rendercount = 0;
-		dev_priv->uncore.fw_mediacount = 0;
 	}
 
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
-void intel_uncore_early_sanitize(struct drm_device *dev)
+void intel_uncore_early_sanitize(struct drm_device *dev, bool restore_forcewake)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
@@ -396,7 +392,7 @@ void intel_uncore_early_sanitize(struct drm_device *dev)
 		__raw_i915_write32(dev_priv, GTFIFODBG,
 				   __raw_i915_read32(dev_priv, GTFIFODBG));
 
-	intel_uncore_forcewake_reset(dev, false);
+	intel_uncore_forcewake_reset(dev, restore_forcewake);
 }
 
 void intel_uncore_sanitize(struct drm_device *dev)
@@ -827,7 +823,7 @@ void intel_uncore_init(struct drm_device *dev)
 	setup_timer(&dev_priv->uncore.force_wake_timer,
 		    gen6_force_wake_timer, (unsigned long)dev_priv);
 
-	intel_uncore_early_sanitize(dev);
+	intel_uncore_early_sanitize(dev, false);
 
 	if (IS_VALLEYVIEW(dev)) {
 		dev_priv->uncore.funcs.force_wake_get = __vlv_force_wake_get;
-- 
1.8.4