drm/i915: Rebalance runtime pm vs forcewake

Calling intel_runtime_pm_put() is illegal from a soft-irq context, so
revert the crude hack

commit aa0b3b5bb8768c1a6a6788869d9c7015eae7e80c
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Tue Apr 1 14:55:07 2014 -0300

    drm/i915: don't schedule force_wake_timer at gen6_read

and apply the single line corrective instead.

v2: assert forcewake is off after the forcewake_reset (Paulo)

References: https://bugs.freedesktop.org/show_bug.cgi?id=80913
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 308774f..55a3fef 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1365,8 +1365,6 @@ static int intel_runtime_suspend(struct device *device)
        if (WARN_ON_ONCE(!HAS_RUNTIME_PM(dev)))
                return -ENODEV;
 
-       assert_force_wake_inactive(dev_priv);
-
        DRM_DEBUG_KMS("Suspending device\n");
 
        /*
@@ -1405,6 +1403,7 @@ static int intel_runtime_suspend(struct device *device)
        }
 
        del_timer_sync(&dev_priv->gpu_error.hangcheck_timer);
+       intel_uncore_forcewake_reset(dev, false);
        dev_priv->pm.suspended = true;
 
        /*
@@ -1432,6 +1431,8 @@ static int intel_runtime_suspend(struct device *device)
                intel_opregion_notify_adapter(dev, PCI_D3hot);
        }
 
+       assert_force_wake_inactive(dev_priv);
+
        DRM_DEBUG_KMS("Device suspended\n");
        return 0;
 }

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index e9561de..b39ed79 100644 (file)
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -449,8 +449,6 @@ static void gen6_force_wake_timer(unsigned long arg)
        if (--dev_priv->uncore.forcewake_count == 0)
                dev_priv->uncore.funcs.force_wake_put(dev_priv, FORCEWAKE_ALL);
        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
-
-       intel_runtime_pm_put(dev_priv);
 }
 
 void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
@@ -586,7 +584,6 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
 void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
 {
        unsigned long irqflags;
-       bool delayed = false;
 
        if (!dev_priv->uncore.funcs.force_wake_put)
                return;
@@ -603,21 +600,19 @@ void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
                goto out;
        }
 
-
        spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
        WARN_ON(!dev_priv->uncore.forcewake_count);
 
        if (--dev_priv->uncore.forcewake_count == 0) {
                dev_priv->uncore.forcewake_count++;
-               delayed = true;
                mod_timer_pinned(&dev_priv->uncore.force_wake_timer,
                                 jiffies + 1);
        }
+
        spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 
 out:
-       if (!delayed)
-               intel_runtime_pm_put(dev_priv);
+       intel_runtime_pm_put(dev_priv);
 }
 
 void assert_force_wake_inactive(struct drm_i915_private *dev_priv)
@@ -774,12 +769,11 @@ gen6_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
            NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
                dev_priv->uncore.funcs.force_wake_get(dev_priv, \
                                                      FORCEWAKE_ALL); \
-               val = __raw_i915_read##x(dev_priv, reg); \
-               dev_priv->uncore.funcs.force_wake_put(dev_priv, \
-                                                     FORCEWAKE_ALL); \
-       } else { \
-               val = __raw_i915_read##x(dev_priv, reg); \
+               dev_priv->uncore.forcewake_count++; \
+               mod_timer_pinned(&dev_priv->uncore.force_wake_timer, \
+                                jiffies + 1); \
        } \
+       val = __raw_i915_read##x(dev_priv, reg); \
        hsw_unclaimed_reg_debug(dev_priv, reg, true, false); \
        REG_READ_FOOTER; \
 }