[PATCH 1/3] drm/panic: Add drm_panic_is_enabled()

[Jocelyn Falempe <jfalempe@redhat.com>]

It allows to check if the drm device supports drm_panic.
Prepare the work to have better integration with fbcon and vtconsole.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
---
 drivers/gpu/drm/drm_panic.c | 20 ++++++++++++++++++++
 include/drm/drm_panic.h     |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 948aed00595e..d9a25c2d0a65 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -703,6 +703,26 @@ static void debugfs_register_plane(struct drm_plane *plane, int index)
 static void debugfs_register_plane(struct drm_plane *plane, int index) {}
 #endif /* CONFIG_DRM_PANIC_DEBUG */
 
+/**
+ * drm_panic_is_enabled
+ * @dev: the drm device that may supports drm_panic
+ *
+ * returns true if the drm device supports drm_panic
+ */
+bool drm_panic_is_enabled(struct drm_device *dev)
+{
+	struct drm_plane *plane;
+
+	if (!dev->mode_config.num_total_plane)
+		return false;
+
+	drm_for_each_plane(plane, dev)
+		if (plane->helper_private && plane->helper_private->get_scanout_buffer)
+			return true;
+	return false;
+}
+EXPORT_SYMBOL(drm_panic_is_enabled);
+
 /**
  * drm_panic_register() - Initialize DRM panic for a device
  * @dev: the drm device on which the panic screen will be displayed.
diff --git a/include/drm/drm_panic.h b/include/drm/drm_panic.h
index 73bb3f3d9ed9..c3a358dc3e27 100644
--- a/include/drm/drm_panic.h
+++ b/include/drm/drm_panic.h
@@ -148,11 +148,13 @@ struct drm_scanout_buffer {
 
 #ifdef CONFIG_DRM_PANIC
 
+bool drm_panic_is_enabled(struct drm_device *dev);
 void drm_panic_register(struct drm_device *dev);
 void drm_panic_unregister(struct drm_device *dev);
 
 #else
 
+bool drm_panic_is_enabled(struct drm_device *dev) {return false; }
 static inline void drm_panic_register(struct drm_device *dev) {}
 static inline void drm_panic_unregister(struct drm_device *dev) {}
 
-- 
2.45.2