[PATCH v4 12/23] drm/tests: helpers: Add a (re)try helper variant to enable CRTC connector

[Cristian Ciocaltea]

Provide a wrapper over drm_kunit_helper_enable_crtc_connector() to
automatically handle EDEADLK.

This is going to help improve the error handling in a bunch of test
cases without open coding the restart of the atomic sequence.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
 drivers/gpu/drm/tests/drm_kunit_helpers.c | 39 +++++++++++++++++++++++++++++++
 include/drm/drm_kunit_helpers.h           |  7 ++++++
 2 files changed, 46 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_kunit_helpers.c b/drivers/gpu/drm/tests/drm_kunit_helpers.c
index 5f7257840d8ef0aeabe5f00802f5037ed652ae66..4e1174c50b1f2b6358eb740cd73c6d86e53d0df9 100644
--- a/drivers/gpu/drm/tests/drm_kunit_helpers.c
+++ b/drivers/gpu/drm/tests/drm_kunit_helpers.c
@@ -332,6 +332,45 @@ int drm_kunit_helper_enable_crtc_connector(struct kunit *test,
 }
 EXPORT_SYMBOL_GPL(drm_kunit_helper_enable_crtc_connector);
 
+/**
+ * drm_kunit_helper_try_enable_crtc_connector - (Re)tries to enable a CRTC -> Connector output
+ * @test: The test context object
+ * @drm: The device to alloc the plane for
+ * @crtc: The CRTC to enable
+ * @connector: The Connector to enable
+ * @mode: The display mode to configure the CRTC with
+ * @ctx: Locking context
+ *
+ * This function is a wrapper over @drm_kunit_helper_enable_crtc_connector
+ * to automatically handle EDEADLK and (re)try to enable the route from
+ * @crtc to @connector, with the given @mode.
+ *
+ * Returns:
+ *
+ * A pointer to the new CRTC, or an ERR_PTR() otherwise.
+ */
+int drm_kunit_helper_try_enable_crtc_connector(struct kunit *test,
+					       struct drm_device *drm,
+					       struct drm_crtc *crtc,
+					       struct drm_connector *connector,
+					       const struct drm_display_mode *mode,
+					       struct drm_modeset_acquire_ctx *ctx)
+{
+	int ret;
+
+retry_enable:
+	ret = drm_kunit_helper_enable_crtc_connector(test, drm, crtc, connector,
+						     mode, ctx);
+	if (ret == -EDEADLK) {
+		ret = drm_modeset_backoff(ctx);
+		if (!ret)
+			goto retry_enable;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_kunit_helper_try_enable_crtc_connector);
+
 static void kunit_action_drm_mode_destroy(void *ptr)
 {
 	struct drm_display_mode *mode = ptr;
diff --git a/include/drm/drm_kunit_helpers.h b/include/drm/drm_kunit_helpers.h
index 4948379237e96163dfda0d2f180c0c564e7d110e..bc6cd2fcc3174fb0996d189d9f6f4d32cf013731 100644
--- a/include/drm/drm_kunit_helpers.h
+++ b/include/drm/drm_kunit_helpers.h
@@ -126,6 +126,13 @@ int drm_kunit_helper_enable_crtc_connector(struct kunit *test,
 					   const struct drm_display_mode *mode,
 					   struct drm_modeset_acquire_ctx *ctx);
 
+int drm_kunit_helper_try_enable_crtc_connector(struct kunit *test,
+					       struct drm_device *drm,
+					       struct drm_crtc *crtc,
+					       struct drm_connector *connector,
+					       const struct drm_display_mode *mode,
+					       struct drm_modeset_acquire_ctx *ctx);
+
 int drm_kunit_add_mode_destroy_action(struct kunit *test,
 				      struct drm_display_mode *mode);
 

-- 
2.49.0