[PATCH 72/79] drm/i915: Enabling rc6 and rps have different requirements, so separate them

[Chris Wilson]

On Ironlake, we are required to not enable rc6 until the GPU is loaded
with a valid context; after that point it can start to use a powersaving
context for rc6. This seems a reasonable requirement to impose on all
generations as we are already priming the system by loading a context on
resume. We can simply then delay enabling rc6 until we know the GPU is
awake.

v2: Reorder intel_gt_pm_fini in i915_gem_fini to match setup ordering,
and remove the superfluous intel_gt_pm_sanitize() on mmio cleanup.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c      |  1 -
 drivers/gpu/drm/i915/i915_gem.c      | 46 ++++++++++++++++++++--------
 drivers/gpu/drm/i915/intel_display.c |  6 ----
 drivers/gpu/drm/i915/intel_gt_pm.c   |  2 ++
 4 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 71b8a78a0c04..b80ef659d31a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1062,7 +1062,6 @@ static int i915_driver_init_mmio(struct drm_i915_private *dev_priv)
  */
 static void i915_driver_cleanup_mmio(struct drm_i915_private *dev_priv)
 {
-	intel_gt_pm_sanitize(dev_priv);
 	intel_uncore_fini(dev_priv);
 	i915_mmio_cleanup(dev_priv);
 	pci_dev_put(dev_priv->bridge_dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 47cbcdac64f1..3251bd1bb266 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -210,10 +210,6 @@ void i915_gem_unpark(struct drm_i915_private *i915)
 	if (unlikely(++i915->gt.epoch == 0)) /* keep 0 as invalid */
 		i915->gt.epoch = 1;
 
-	intel_gt_pm_enable_rps(i915);
-	intel_gt_pm_enable_rc6(i915);
-	intel_gt_pm_enable_llc(i915);
-
 	i915_update_gfx_val(i915);
 	if (INTEL_GEN(i915) >= 6)
 		gen6_rps_busy(i915);
@@ -4634,6 +4630,33 @@ void i915_gem_suspend_late(struct drm_i915_private *i915)
 	i915_gem_sanitize(i915);
 }
 
+static int load_power_context(struct drm_i915_private *i915)
+{
+	int err;
+
+	intel_gt_pm_sanitize(i915);
+	intel_gt_pm_enable_rps(i915);
+
+	err = i915_gem_switch_to_kernel_context(i915);
+	if (err)
+		goto err;
+
+	if (i915_gem_wait_for_idle(i915, I915_WAIT_LOCKED, HZ / 5)) {
+		i915_gem_set_wedged(i915);
+		err = -EIO; /* Caller will declare us wedged */
+		goto err;
+	}
+
+	intel_gt_pm_enable_rc6(i915);
+	intel_gt_pm_enable_llc(i915);
+
+	return 0;
+
+err:
+	intel_gt_pm_sanitize(i915);
+	return err;
+}
+
 void i915_gem_resume(struct drm_i915_private *i915)
 {
 	GEM_TRACE("\n");
@@ -4659,7 +4682,7 @@ void i915_gem_resume(struct drm_i915_private *i915)
 	intel_uc_resume(i915);
 
 	/* Always reload a context for powersaving. */
-	if (i915_gem_switch_to_kernel_context(i915))
+	if (load_power_context(i915))
 		goto err_wedged;
 
 out_unlock:
@@ -4669,7 +4692,8 @@ void i915_gem_resume(struct drm_i915_private *i915)
 
 err_wedged:
 	if (!i915_terminally_wedged(&i915->gpu_error)) {
-		DRM_ERROR("failed to re-initialize GPU, declaring wedged!\n");
+		dev_err(i915->drm.dev,
+			"Failed to re-initialize GPU, declaring wedged!\n");
 		i915_gem_set_wedged(i915);
 	}
 	goto out_unlock;
@@ -4864,16 +4888,11 @@ static int __intel_engines_record_defaults(struct drm_i915_private *i915)
 			goto err_active;
 	}
 
-	err = i915_gem_switch_to_kernel_context(i915);
+	/* Flush the default context image to memory, and enable powersaving. */
+	err = load_power_context(i915);
 	if (err)
 		goto err_active;
 
-	if (i915_gem_wait_for_idle(i915, I915_WAIT_LOCKED, HZ / 5)) {
-		i915_gem_set_wedged(i915);
-		err = -EIO; /* Caller will declare us wedged */
-		goto err_active;
-	}
-
 	assert_kernel_context_is_current(i915);
 
 	for_each_engine(engine, i915, id) {
@@ -5119,6 +5138,7 @@ void i915_gem_fini(struct drm_i915_private *dev_priv)
 	intel_uc_fini(dev_priv);
 	i915_gem_cleanup_engines(dev_priv);
 	i915_gem_contexts_fini(dev_priv);
+	intel_gt_pm_fini(dev_priv);
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
 	intel_uc_fini_misc(dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 29e77d9c4b0f..c49e99a65e63 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -16016,10 +16016,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
 	flush_work(&dev_priv->atomic_helper.free_work);
 	WARN_ON(!llist_empty(&dev_priv->atomic_helper.free_list));
 
-	intel_gt_pm_disable_llc(dev_priv);
-	intel_gt_pm_disable_rc6(dev_priv);
-	intel_gt_pm_disable_rps(dev_priv);
-
 	/*
 	 * Interrupts and polling as the first thing to avoid creating havoc.
 	 * Too much stuff here (turning of connectors, ...) would
@@ -16047,8 +16043,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
 
 	intel_cleanup_overlay(dev_priv);
 
-	intel_gt_pm_fini(dev_priv);
-
 	intel_teardown_gmbus(dev_priv);
 
 	destroy_workqueue(dev_priv->modeset_wq);
diff --git a/drivers/gpu/drm/i915/intel_gt_pm.c b/drivers/gpu/drm/i915/intel_gt_pm.c
index 600660dca54a..76c8df994a50 100644
--- a/drivers/gpu/drm/i915/intel_gt_pm.c
+++ b/drivers/gpu/drm/i915/intel_gt_pm.c
@@ -2768,6 +2768,8 @@ void intel_gt_pm_disable_llc(struct drm_i915_private *i915)
 
 void intel_gt_pm_fini(struct drm_i915_private *i915)
 {
+	intel_gt_pm_sanitize(i915);
+
 	if (IS_VALLEYVIEW(i915))
 		valleyview_cleanup_gt_powersave(i915);
 
-- 
2.18.0