[PATCH v3 09/14] drm/panic: Split draw_panic_plane()

Thomas Zimmermann tzimmermann at suse.de
Wed Sep 2 05:13:17 PDT 2026


Move locking and parameters from draw_panic_plane() into the new
helper drm_panic_display_panic_screen(). Call draw_panic_plane() from
there.

The new helper drm_panic_display_panic_screen() is now the DRM core's
interface for displaying a panic screen. The code remaining in
draw_panic_plane() still does all the heavy lifting. It will become a
plane helper for DRM drivers.

v2:
- use panic_type argument in draw_panic_plane() (Sashiko)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
---
 drivers/gpu/drm/drm_panic.c | 62 ++++++++++++++++++++-----------------
 1 file changed, 34 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
index 690e96e8f1f9..624042c42a7f 100644
--- a/drivers/gpu/drm/drm_panic.c
+++ b/drivers/gpu/drm/drm_panic.c
@@ -936,42 +936,25 @@ static void drm_panic_clear_description(void)
 	desc_line->txt = NULL;
 }
 
-static void draw_panic_plane(struct drm_plane *plane, const char *description)
+static void draw_panic_plane(struct drm_plane *plane, const char *description,
+			     enum drm_panic_type panic_type, u32 fg_color, u32 bg_color,
+			     unsigned int qr_version)
 {
 	struct drm_scanout_buffer sb = { };
 	int ret;
-	unsigned long flags;
-#if defined(CONFIG_DRM_PANIC_FOREGROUND_COLOR)
-	u32 fg_color = CONFIG_DRM_PANIC_FOREGROUND_COLOR;
-#else
-	u32 fg_color = 0x00ffffff;
-#endif
-#if defined(CONFIG_DRM_PANIC_BACKGROUND_COLOR)
-	u32 bg_color = CONFIG_DRM_PANIC_BACKGROUND_COLOR;
-#else
-	u32 bg_color = 0x00000000;
-#endif
-#if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
-	unsigned int qr_version = panic_qr_version;
-#else
-	unsigned int qr_version = 0;
-#endif
-
-	if (!drm_panic_trylock(plane->dev, flags))
-		return;
 
 	ret = plane->helper_private->get_scanout_buffer(plane, &sb);
 
 	if (ret || !drm_panic_is_format_supported(sb.format))
-		goto unlock;
+		return;
 
 	/* One of these should be set, or it can't draw pixels */
 	if (!sb.set_pixel && !sb.pages && iosys_map_is_null(&sb.map[0]))
-		goto unlock;
+		return;
 
 	drm_panic_set_description(description);
 
-	ret = draw_panic_dispatch(&sb, drm_panic_type, fg_color, bg_color, qr_version);
+	ret = draw_panic_dispatch(&sb, panic_type, fg_color, bg_color, qr_version);
 	if (!ret) {
 		/*
 		 * Only flush if we have a panic screen to display. Otherwise
@@ -982,9 +965,33 @@ static void draw_panic_plane(struct drm_plane *plane, const char *description)
 	}
 
 	drm_panic_clear_description();
+}
 
-unlock:
-	drm_panic_unlock(plane->dev, flags);
+static void drm_panic_display_panic_screen(struct drm_plane *plane, const char *description)
+{
+#if defined(CONFIG_DRM_PANIC_FOREGROUND_COLOR)
+	u32 fg_color = CONFIG_DRM_PANIC_FOREGROUND_COLOR;
+#else
+	u32 fg_color = 0x00ffffff;
+#endif
+#if defined(CONFIG_DRM_PANIC_BACKGROUND_COLOR)
+	u32 bg_color = CONFIG_DRM_PANIC_BACKGROUND_COLOR;
+#else
+	u32 bg_color = 0x00000000;
+#endif
+#if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
+	unsigned int qr_version = panic_qr_version;
+#else
+	unsigned int qr_version = 0;
+#endif
+	struct drm_device *dev = plane->dev;
+	unsigned long flags;
+
+	if (drm_panic_trylock(dev, flags)) {
+		draw_panic_plane(plane, description, drm_panic_type,
+				 fg_color, bg_color, qr_version);
+		drm_panic_unlock(dev, flags);
+	}
 }
 
 static struct drm_plane *to_drm_plane(struct kmsg_dumper *kd)
@@ -997,10 +1004,9 @@ static void drm_panic(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detai
 	struct drm_plane *plane = to_drm_plane(dumper);
 
 	if (detail->reason == KMSG_DUMP_PANIC)
-		draw_panic_plane(plane, detail->description);
+		drm_panic_display_panic_screen(plane, detail->description);
 }
 
-
 /*
  * DEBUG FS, This is currently unsafe.
  * Create one file per plane, so it's possible to debug one plane at a time.
@@ -1017,7 +1023,7 @@ static ssize_t debugfs_trigger_write(struct file *file, const char __user *user_
 	if (kstrtobool_from_user(user_buf, count, &run) == 0 && run) {
 		struct drm_plane *plane = file->private_data;
 
-		draw_panic_plane(plane, "Test from debugfs");
+		drm_panic_display_panic_screen(plane, "Test from debugfs");
 	}
 	return count;
 }
-- 
2.55.0




More information about the linux-arm-kernel mailing list