drm/i915: Enable RC6 immediately

Now that PCU communication is reasonably fast, we do not need to defer
RC6 initialisation to a workqueue.

References: https://bugs.freedesktop.org/show_bug.cgi?id=97017
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/i915_drv.c

@@ -1630,7 +1630,6 @@ static int i915_drm_resume(struct drm_device *dev)
 
 	intel_opregion_notify_adapter(dev_priv, PCI_D0);
 
-	intel_autoenable_gt_powersave(dev_priv);
 	drm_kms_helper_poll_enable(dev);
 
 	enable_rpm_wakeref_asserts(dev_priv);
@@ -1812,7 +1811,8 @@ int i915_reset(struct drm_i915_private *dev_priv)
 	 * previous concerns that it doesn't respond well to some forms
 	 * of re-init after reset.
 	 */
-	intel_autoenable_gt_powersave(dev_priv);
+	if (INTEL_GEN(dev_priv) > 5)
+		intel_enable_gt_powersave(dev_priv);
 
 	return 0;
 
@@ -2440,6 +2440,7 @@ static int intel_runtime_resume(struct device *device)
 	i915_gem_init_swizzling(dev);
 
 	intel_runtime_pm_enable_interrupts(dev_priv);
+	intel_enable_gt_powersave(dev_priv);
 
 	/*
 	 * On VLV/CHV display interrupts are part of the display

drivers/gpu/drm/i915/i915_drv.h

@@ -1192,7 +1192,6 @@ struct intel_gen6_power_mgmt {
 	bool client_boost;
 
 	bool enabled;
-	struct delayed_work autoenable_work;
 	unsigned boosts;
 
 	/* manual wa residency calculations */

drivers/gpu/drm/i915/i915_gem.c

@@ -4355,8 +4355,6 @@ i915_gem_suspend(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	int ret = 0;
 
-	intel_suspend_gt_powersave(dev_priv);
-
 	mutex_lock(&dev->struct_mutex);
 
 	/* We have to flush all the executing contexts to main memory so

drivers/gpu/drm/i915/i915_gem_request.c

@@ -405,7 +405,6 @@ static void i915_gem_mark_busy(const struct intel_engine_cs *engine)
 	intel_runtime_pm_get_noresume(dev_priv);
 	dev_priv->gt.awake = true;
 
-	intel_enable_gt_powersave(dev_priv);
 	i915_update_gfx_val(dev_priv);
 	if (INTEL_GEN(dev_priv) >= 6)
 		gen6_rps_busy(dev_priv);

drivers/gpu/drm/i915/intel_display.c

@@ -15502,6 +15502,7 @@ void intel_modeset_init_hw(struct drm_device *dev)
 	dev_priv->atomic_cdclk_freq = dev_priv->cdclk_freq;
 
 	intel_init_clock_gating(dev);
+	intel_enable_gt_powersave(dev_priv);
 }
 
 /*

drivers/gpu/drm/i915/intel_drv.h

@@ -1691,12 +1691,9 @@ void intel_pm_setup(struct drm_device *dev);
 void intel_gpu_ips_init(struct drm_i915_private *dev_priv);
 void intel_gpu_ips_teardown(void);
 void intel_init_gt_powersave(struct drm_i915_private *dev_priv);
-void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv);
-void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_enable_gt_powersave(struct drm_i915_private *dev_priv);
-void intel_autoenable_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_disable_gt_powersave(struct drm_i915_private *dev_priv);
-void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv);
+void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv);
 void gen6_rps_busy(struct drm_i915_private *dev_priv);
 void gen6_rps_reset_ei(struct drm_i915_private *dev_priv);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_pm.c

@@ -6526,8 +6526,6 @@ void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
 	dev_priv->rps.boost_freq = dev_priv->rps.max_freq;
 
 	mutex_unlock(&dev_priv->rps.hw_lock);
-
-	intel_autoenable_gt_powersave(dev_priv);
 }
 
 void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
@@ -6541,31 +6539,10 @@ void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
 		intel_runtime_pm_put(dev_priv);
 }
 
-/**
- * intel_suspend_gt_powersave - suspend PM work and helper threads
- * @dev_priv: i915 device
- *
- * We don't want to disable RC6 or other features here, we just want
- * to make sure any work we've queued has finished and won't bother
- * us while we're suspended.
- */
-void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv)
-{
-	if (INTEL_GEN(dev_priv) < 6)
-		return;
-
-	if (cancel_delayed_work_sync(&dev_priv->rps.autoenable_work))
-		intel_runtime_pm_put(dev_priv);
-
-	/* gen6_rps_idle() will be called later to disable interrupts */
-}
-
 void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv)
 {
 	dev_priv->rps.enabled = true; /* force disabling */
 	intel_disable_gt_powersave(dev_priv);
-
-	gen6_reset_rps_interrupts(dev_priv);
 }
 
 void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
@@ -6590,13 +6567,12 @@ void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
 
 	dev_priv->rps.enabled = false;
 	mutex_unlock(&dev_priv->rps.hw_lock);
+
+	gen6_reset_rps_interrupts(dev_priv);
 }
 
 void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
 {
-	/* We shouldn't be disabling as we submit, so this should be less
-	 * racy than it appears!
-	 */
 	if (READ_ONCE(dev_priv->rps.enabled))
 		return;
 
@@ -6632,75 +6608,9 @@ void intel_enable_gt_powersave(struct drm_i915_private *dev_priv)
 	WARN_ON(dev_priv->rps.efficient_freq < dev_priv->rps.min_freq);
 	WARN_ON(dev_priv->rps.efficient_freq > dev_priv->rps.max_freq);
 
-	dev_priv->rps.enabled = true;
 	mutex_unlock(&dev_priv->rps.hw_lock);
 }
 
-static void __intel_autoenable_gt_powersave(struct work_struct *work)
-{
-	struct drm_i915_private *dev_priv =
-		container_of(work, typeof(*dev_priv), rps.autoenable_work.work);
-	struct intel_engine_cs *rcs;
-	struct drm_i915_gem_request *req;
-
-	if (READ_ONCE(dev_priv->rps.enabled))
-		goto out;
-
-	rcs = &dev_priv->engine[RCS];
-	if (rcs->last_context)
-		goto out;
-
-	if (!rcs->init_context)
-		goto out;
-
-	mutex_lock(&dev_priv->drm.struct_mutex);
-
-	req = i915_gem_request_alloc(rcs, dev_priv->kernel_context);
-	if (IS_ERR(req))
-		goto unlock;
-
-	if (!i915.enable_execlists && i915_switch_context(req) == 0)
-		rcs->init_context(req);
-
-	/* Mark the device busy, calling intel_enable_gt_powersave() */
-	i915_add_request_no_flush(req);
-
-unlock:
-	mutex_unlock(&dev_priv->drm.struct_mutex);
-out:
-	intel_runtime_pm_put(dev_priv);
-}
-
-void intel_autoenable_gt_powersave(struct drm_i915_private *dev_priv)
-{
-	if (READ_ONCE(dev_priv->rps.enabled))
-		return;
-
-	if (IS_IRONLAKE_M(dev_priv)) {
-		ironlake_enable_drps(dev_priv);
-		mutex_lock(&dev_priv->drm.struct_mutex);
-		intel_init_emon(dev_priv);
-		mutex_unlock(&dev_priv->drm.struct_mutex);
-	} else if (INTEL_INFO(dev_priv)->gen >= 6) {
-		/*
-		 * PCU communication is slow and this doesn't need to be
-		 * done at any specific time, so do this out of our fast path
-		 * to make resume and init faster.
-		 *
-		 * We depend on the HW RC6 power context save/restore
-		 * mechanism when entering D3 through runtime PM suspend. So
-		 * disable RPM until RPS/RC6 is properly setup. We can only
-		 * get here via the driver load/system resume/runtime resume
-		 * paths, so the _noresume version is enough (and in case of
-		 * runtime resume it's necessary).
-		 */
-		if (queue_delayed_work(dev_priv->wq,
-				       &dev_priv->rps.autoenable_work,
-				       round_jiffies_up_relative(HZ)))
-			intel_runtime_pm_get_noresume(dev_priv);
-	}
-}
-
 static void ibx_init_clock_gating(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -7806,8 +7716,6 @@ void intel_pm_setup(struct drm_device *dev)
 	mutex_init(&dev_priv->rps.hw_lock);
 	spin_lock_init(&dev_priv->rps.client_lock);
 
-	INIT_DELAYED_WORK(&dev_priv->rps.autoenable_work,
-			  __intel_autoenable_gt_powersave);
 	INIT_LIST_HEAD(&dev_priv->rps.clients);
 
 	dev_priv->pm.suspended = false;

drivers/gpu/drm/i915/intel_uncore.c

@@ -435,7 +435,7 @@ void intel_uncore_sanitize(struct drm_i915_private *dev_priv)
 	i915.enable_rc6 = sanitize_rc6_option(dev_priv, i915.enable_rc6);
 
 	/* BIOS often leaves RC6 enabled, but disable it for hw init */
-	intel_sanitize_gt_powersave(dev_priv);
+	intel_disable_gt_powersave(dev_priv);
 }
 
 static void __intel_uncore_forcewake_get(struct drm_i915_private *dev_priv,