From e636c8d336489bf3eed5878299e6cc045bbad077 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:17:29 +0000
Subject: [PATCH] debug lk

---
 kernel/drivers/gpu/drm/drm_modeset_helper.c |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/kernel/drivers/gpu/drm/drm_modeset_helper.c b/kernel/drivers/gpu/drm/drm_modeset_helper.c
index f1c24ab..da48312 100644
--- a/kernel/drivers/gpu/drm/drm_modeset_helper.c
+++ b/kernel/drivers/gpu/drm/drm_modeset_helper.c
@@ -21,10 +21,12 @@
  */
 
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
 
 /**
  * DOC: aux kms helpers
@@ -146,6 +148,21 @@
  * Initialize a CRTC object with a default helper-provided primary plane and no
  * cursor plane.
  *
+ * Note that we make some assumptions about hardware limitations that may not be
+ * true for all hardware:
+ *
+ * 1. Primary plane cannot be repositioned.
+ * 2. Primary plane cannot be scaled.
+ * 3. Primary plane must cover the entire CRTC.
+ * 4. Subpixel positioning is not supported.
+ * 5. The primary plane must always be on if the CRTC is enabled.
+ *
+ * This is purely a backwards compatibility helper for old drivers. Drivers
+ * should instead implement their own primary plane. Atomic drivers must do so.
+ * Drivers with the above hardware restriction can look into using &struct
+ * drm_simple_display_pipe, which encapsulates the above limitations into a nice
+ * interface.
+ *
  * Returns:
  * Zero on success, error code on failure.
  */

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