[PATCH] drm/i915/selftests: align more to real device lifetimes

[Daniel Vetter]

To avoid having to create all the device and driver scaffolding we
just manually create and destroy a devres_group.

v2: Rebased

v3: use devres_open/release_group so we can use devm without real
hacks in the driver core or having to create an entire fake bus for
testing drivers. Might want to extract this into helpers eventually,
maybe as a mock_drm_dev_alloc or test_drm_dev_alloc.

v4:
- Fix IS_ERR handling (Matt)
- Delete surplus put_device() in mock_device_release (intel-gfx-ci)

v5:
- do not switch to device_add - it breaks runtime pm in the tests and
  with the devres_group_add/release no longer needed for automatic
  cleanup (CI). Update commit message to match.
- print correct error in pr_err (Matt)

Cc: Matthew Auld <matthew.william.auld at gmail.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com> (v3)
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Reviewed-by: Matthew Auld <matthew.william.auld at gmail.com> (v4)
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 .../gpu/drm/i915/selftests/mock_gem_device.c  | 38 +++++++++----------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index ac600d395c8f..3b574597cd7f 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -79,8 +79,6 @@ static void mock_device_release(struct drm_device *dev)
 
 out:
 	i915_params_free(&i915->params);
-	put_device(&i915->drm.pdev->dev);
-	i915->drm.pdev = NULL;
 }
 
 static struct drm_driver mock_driver = {
@@ -128,12 +126,6 @@ struct drm_i915_private *mock_gem_device(void)
 	pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
 	if (!pdev)
 		return NULL;
-	i915 = kzalloc(sizeof(*i915), GFP_KERNEL);
-	if (!i915) {
-		kfree(pdev);
-		return NULL;
-	}
-
 	device_initialize(&pdev->dev);
 	pdev->class = PCI_BASE_CLASS_DISPLAY << 16;
 	pdev->dev.release = release_dev;
@@ -144,8 +136,23 @@ struct drm_i915_private *mock_gem_device(void)
 	/* HACK to disable iommu for the fake device; force identity mapping */
 	pdev->dev.iommu = &fake_iommu;
 #endif
+	if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
+		put_device(&pdev->dev);
+		return NULL;
+	}
+
+	i915 = devm_drm_dev_alloc(&pdev->dev, &mock_driver,
+				  struct drm_i915_private, drm);
+	if (IS_ERR(i915)) {
+		pr_err("Failed to allocate mock GEM device: err=%d\n", PTR_ERR(i915));
+		devres_release_group(&pdev->dev, NULL);
+		put_device(&pdev->dev);
+
+		return NULL;
+	}
 
 	pci_set_drvdata(pdev, i915);
+	i915->drm.pdev = pdev;
 
 	dev_pm_domain_set(&pdev->dev, &pm_domain);
 	pm_runtime_enable(&pdev->dev);
@@ -153,16 +160,6 @@ struct drm_i915_private *mock_gem_device(void)
 	if (pm_runtime_enabled(&pdev->dev))
 		WARN_ON(pm_runtime_get_sync(&pdev->dev));
 
-	err = drm_dev_init(&i915->drm, &mock_driver, &pdev->dev);
-	if (err) {
-		pr_err("Failed to initialise mock GEM device: err=%d\n", err);
-		put_device(&pdev->dev);
-		kfree(i915);
-
-		return NULL;
-	}
-	i915->drm.pdev = pdev;
-	drmm_add_final_kfree(&i915->drm, i915);
 
 	i915_params_copy(&i915->params, &i915_modparams);
 
@@ -229,5 +226,8 @@ struct drm_i915_private *mock_gem_device(void)
 
 void mock_destroy_device(struct drm_i915_private *i915)
 {
-	drm_dev_put(&i915->drm);
+	struct device *dev = i915->drm.dev;
+
+	devres_release_group(dev, NULL);
+	put_device(dev);
 }
-- 
2.28.0