[PATCH 23/29] mutexless-suspend

[Chris Wilson]

---
 drivers/gpu/drm/i915/i915_drv.c | 14 +++-----
 drivers/gpu/drm/i915/i915_drv.h |  2 +-
 drivers/gpu/drm/i915/i915_gem.c | 64 +++++++++++----------------------
 3 files changed, 25 insertions(+), 55 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0db3c83cce29..a755aa9984e0 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -696,8 +696,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	return 0;
 
 cleanup_gem:
-	if (i915_gem_suspend(dev_priv))
-		DRM_ERROR("failed to idle hardware; continuing to unload!\n");
+	i915_gem_suspend(dev_priv);
 	i915_gem_fini(dev_priv);
 cleanup_irq:
 	drm_irq_uninstall(dev);
@@ -1425,8 +1424,7 @@ void i915_driver_unload(struct drm_device *dev)
 
 	i915_driver_unregister(dev_priv);
 
-	if (i915_gem_suspend(dev_priv))
-		DRM_ERROR("failed to idle hardware; continuing to unload!\n");
+	i915_gem_suspend(dev_priv);
 
 	intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
 
@@ -1538,7 +1536,6 @@ static bool suspend_to_idle(struct drm_i915_private *dev_priv)
 static int i915_drm_prepare(struct drm_device *dev)
 {
 	struct drm_i915_private *i915 = to_i915(dev);
-	int err;
 
 	/*
 	 * NB intel_display_suspend() may issue new requests after we've
@@ -1546,12 +1543,9 @@ static int i915_drm_prepare(struct drm_device *dev)
 	 * split out that work and pull it forward so that after point,
 	 * the GPU is not woken again.
 	 */
-	err = i915_gem_suspend(i915);
-	if (err)
-		dev_err(&i915->drm.pdev->dev,
-			"GEM idle failed, suspend/resume might fail\n");
+	i915_gem_suspend(i915);
 
-	return err;
+	return 0;
 }
 
 static int i915_drm_suspend(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 931792e1a205..c47ade21de27 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3180,7 +3180,7 @@ void i915_gem_fini(struct drm_i915_private *dev_priv);
 void i915_gem_cleanup_engines(struct drm_i915_private *dev_priv);
 int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
 			   unsigned int flags);
-int __must_check i915_gem_suspend(struct drm_i915_private *dev_priv);
+void i915_gem_suspend(struct drm_i915_private *dev_priv);
 void i915_gem_suspend_late(struct drm_i915_private *dev_priv);
 void i915_gem_resume(struct drm_i915_private *dev_priv);
 vm_fault_t i915_gem_fault(struct vm_fault *vmf);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7ab07036d20c..2d53518ee06d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5040,66 +5040,42 @@ void i915_gem_sanitize(struct drm_i915_private *i915)
 	mutex_unlock(&i915->drm.struct_mutex);
 }
 
-int i915_gem_suspend(struct drm_i915_private *dev_priv)
+void i915_gem_suspend(struct drm_i915_private *i915)
 {
-	struct drm_device *dev = &dev_priv->drm;
-	int ret;
-
 	GEM_TRACE("\n");
 
-	intel_runtime_pm_get(dev_priv);
-	intel_suspend_gt_powersave(dev_priv);
+	intel_runtime_pm_get(i915);
+	intel_suspend_gt_powersave(i915);
 
-	mutex_lock(&dev->struct_mutex);
+	i915_gem_wait_for_idle(i915, I915_WAIT_FOR_IDLE_BOOST);
+
+	intel_uc_suspend(i915);
 
-	/* We have to flush all the executing contexts to main memory so
+	cancel_delayed_work_sync(&i915->gpu_error.hangcheck_work);
+	cancel_delayed_work_sync(&i915->gt.retire_work);
+
+	/*
+	 * We have to flush all the executing contexts to main memory so
 	 * that they can saved in the hibernation image. To ensure the last
 	 * context image is coherent, we have to switch away from it. That
-	 * leaves the dev_priv->kernel_context still active when
+	 * leaves the i915->kernel_context still active when
 	 * we actually suspend, and its image in memory may not match the GPU
 	 * state. Fortunately, the kernel_context is disposable and we do
 	 * not rely on its state.
-	 */
-	if (!i915_terminally_wedged(&dev_priv->gpu_error)) {
-		ret = i915_gem_switch_to_kernel_context(dev_priv);
-		if (ret)
-			goto err_unlock;
-
-		ret = i915_gem_wait_for_idle(dev_priv,
-					     I915_WAIT_INTERRUPTIBLE |
-					     I915_WAIT_LOCKED |
-					     I915_WAIT_FOR_IDLE_BOOST);
-		if (ret && ret != -EIO)
-			goto err_unlock;
-
-		assert_kernel_context_is_current(dev_priv);
-	}
-	mutex_unlock(&dev->struct_mutex);
-
-	intel_uc_suspend(dev_priv);
-
-	cancel_delayed_work_sync(&dev_priv->gpu_error.hangcheck_work);
-	cancel_delayed_work_sync(&dev_priv->gt.retire_work);
-
-	/* As the idle_work is rearming if it detects a race, play safe and
+	 *
+	 * As the idle_work is rearming if it detects a race, play safe and
 	 * repeat the flush until it is definitely idle.
 	 */
-	drain_delayed_work(&dev_priv->gt.idle_work);
+	drain_delayed_work(&i915->gt.idle_work);
 
 	/* Assert that we sucessfully flushed all the work and
 	 * reset the GPU back to its idle, low power state.
 	 */
-	WARN_ON(dev_priv->gt.awake);
-	if (WARN_ON(!intel_engines_are_idle(dev_priv)))
-		i915_gem_set_wedged(dev_priv); /* no hope, discard everything */
-
-	intel_runtime_pm_put(dev_priv);
-	return 0;
+	WARN_ON(i915->gt.awake);
+	if (WARN_ON(!intel_engines_are_idle(i915)))
+		i915_gem_set_wedged(i915); /* no hope, discard everything */
 
-err_unlock:
-	mutex_unlock(&dev->struct_mutex);
-	intel_runtime_pm_put(dev_priv);
-	return ret;
+	intel_runtime_pm_put(i915);
 }
 
 void i915_gem_suspend_late(struct drm_i915_private *i915)
@@ -5551,7 +5527,7 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 err_init_hw:
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
-	WARN_ON(i915_gem_suspend(dev_priv));
+	i915_gem_suspend(dev_priv);
 	i915_gem_suspend_late(dev_priv);
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
-- 
2.18.0