drm/panic: Add drm_panic_is_enabled()

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>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20240717090102.968152-2-jfalempe@redhat.com

diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 20e9d7b206a21aff041bff7559d63509b0dd8357..c10de39cbe831bb88263f1f0dd7c2d318e4bd33c 100644 (file)
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -317,4 +317,11 @@ drm_edid_load_firmware(struct drm_connector *connector)
 }
 #endif
 
+/* drm_panic.c */
+#ifdef CONFIG_DRM_PANIC
+bool drm_panic_is_enabled(struct drm_device *dev);
+#else
+bool drm_panic_is_enabled(struct drm_device *dev) {return false; }
+#endif
+
 #endif /* __DRM_CRTC_INTERNAL_H__ */

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 8794c7f6c0eef0230a96909d51dbb56ed702beb1..9f1a3568e62de9a0b4250fe164d8c602882176a6 100644 (file)
--- 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.