linux-kernel - [PATCH 2/2] vt: Remove con_debug_enter/

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Message-ID: <20251208102851.40894-3-tzimmermann@suse.de>
Date: Mon,  8 Dec 2025 11:17:34 +0100
From: Thomas Zimmermann <tzimmermann@...e.de>
To: gregkh@...uxfoundation.org,
	jirislaby@...nel.org,
	simona@...ll.ch,
	airlied@...il.com
Cc: linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	Thomas Zimmermann <tzimmermann@...e.de>
Subject: [PATCH 2/2] vt: Remove con_debug_enter/_leave from struct consw

There are no implementations of con_debug_enter and con_debug_leave.
Remove the callbacks from struct consw and clean up the caller.

This is a functional revert of commit b45cfba4e900 ("vt,console,kdb:
implement atomic console enter/leave functions").

Signed-off-by: Thomas Zimmermann <tzimmermann@...e.de>
---
 drivers/tty/vt/vt.c     | 30 +-----------------------------
 include/linux/console.h |  8 --------
 2 files changed, 1 insertion(+), 37 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 86a510e5f3d7..0bc3ea12b415 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -187,19 +187,12 @@ static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
  * fg_console is the current virtual console,
  * last_console is the last used one,
  * want_console is the console we want to switch to,
- * saved_* variants are for save/restore around kernel debugger enter/leave
  */
 int fg_console;
 EXPORT_SYMBOL(fg_console);
 int last_console;
 int want_console = -1;
 
-static int saved_fg_console;
-static int saved_last_console;
-static int saved_want_console;
-static int saved_vc_mode;
-static int saved_console_blanked;
-
 /*
  * For each existing display, we have a pointer to console currently visible
  * on that display, allowing consoles other than fg_console to be refreshed
@@ -4287,15 +4280,6 @@ EXPORT_SYMBOL(con_is_visible);
  */
 void con_debug_enter(struct vc_data *vc)
 {
-	saved_fg_console = fg_console;
-	saved_last_console = last_console;
-	saved_want_console = want_console;
-	saved_vc_mode = vc->vc_mode;
-	saved_console_blanked = console_blanked;
-	vc->vc_mode = KD_TEXT;
-	console_blanked = 0;
-	if (vc->vc_sw->con_debug_enter)
-		vc->vc_sw->con_debug_enter(vc);
 #ifdef CONFIG_KGDB_KDB
 	/* Set the initial LINES variable if it is not already set */
 	if (vc->vc_rows < 999) {
@@ -4335,19 +4319,7 @@ EXPORT_SYMBOL_GPL(con_debug_enter);
  * was invoked.
  */
 void con_debug_leave(void)
-{
-	struct vc_data *vc;
-
-	fg_console = saved_fg_console;
-	last_console = saved_last_console;
-	want_console = saved_want_console;
-	console_blanked = saved_console_blanked;
-	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
-
-	vc = vc_cons[fg_console].d;
-	if (vc->vc_sw->con_debug_leave)
-		vc->vc_sw->con_debug_leave(vc);
-}
+{ }
 EXPORT_SYMBOL_GPL(con_debug_leave);
 
 static int do_register_con_driver(const struct consw *csw, int first, int last)
diff --git a/include/linux/console.h b/include/linux/console.h
index 031a58dc2b91..99d67fc41fb5 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -78,12 +78,6 @@ enum vc_intensity;
  *		characters. (optional)
  * @con_invert_region: invert a region of length @count on @vc starting at @p.
  *		(optional)
- * @con_debug_enter: prepare the console for the debugger. This includes, but
- *		is not limited to, unblanking the console, loading an
- *		appropriate palette, and allowing debugger generated output.
- *		(optional)
- * @con_debug_leave: restore the console to its pre-debug state as closely as
- *		possible. (optional)
  */
 struct consw {
 	struct module *owner;
@@ -122,8 +116,6 @@ struct consw {
 			enum vc_intensity intensity,
 			bool blink, bool underline, bool reverse, bool italic);
 	void	(*con_invert_region)(struct vc_data *vc, u16 *p, int count);
-	void	(*con_debug_enter)(struct vc_data *vc);
-	void	(*con_debug_leave)(struct vc_data *vc);
 };
 
 extern const struct consw *conswitchp;
-- 
2.52.0