tty: vt: make consw::con_debug_*() return void

The return value of con_debug_enter() and con_debug_leave() is ignored
on many fronts. So just don't propagate errors (the current
implementations return 0 anyway) and make the return type a void.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-20-jirislaby@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/vt/vt.c

@@ -4012,15 +4012,9 @@ EXPORT_SYMBOL(con_is_visible);
  * Called when the console is taken over by the kernel debugger, this
  * function needs to save the current console state, then put the console
  * into a state suitable for the kernel debugger.
- *
- * RETURNS:
- * Zero on success, nonzero if a failure occurred when trying to prepare
- * the console for the debugger.
  */
-int con_debug_enter(struct vc_data *vc)
+void con_debug_enter(struct vc_data *vc)
 {
-	int ret = 0;
-
 	saved_fg_console = fg_console;
 	saved_last_console = last_console;
 	saved_want_console = want_console;
@@ -4029,7 +4023,7 @@ int con_debug_enter(struct vc_data *vc)
 	vc->vc_mode = KD_TEXT;
 	console_blanked = 0;
 	if (vc->vc_sw->con_debug_enter)
-		ret = vc->vc_sw->con_debug_enter(vc);
+		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) {
@@ -4059,7 +4053,6 @@ int con_debug_enter(struct vc_data *vc)
 		}
 	}
 #endif /* CONFIG_KGDB_KDB */
-	return ret;
 }
 EXPORT_SYMBOL_GPL(con_debug_enter);
 
@@ -4068,15 +4061,10 @@ EXPORT_SYMBOL_GPL(con_debug_enter);
  *
  * Restore the console state to what it was before the kernel debugger
  * was invoked.
- *
- * RETURNS:
- * Zero on success, nonzero if a failure occurred when trying to restore
- * the console.
  */
-int con_debug_leave(void)
+void con_debug_leave(void)
 {
 	struct vc_data *vc;
-	int ret = 0;
 
 	fg_console = saved_fg_console;
 	last_console = saved_last_console;
@@ -4086,8 +4074,7 @@ int con_debug_leave(void)
 
 	vc = vc_cons[fg_console].d;
 	if (vc->vc_sw->con_debug_leave)
-		ret = vc->vc_sw->con_debug_leave(vc);
-	return ret;
+		vc->vc_sw->con_debug_leave(vc);
 }
 EXPORT_SYMBOL_GPL(con_debug_leave);
 

drivers/video/fbdev/core/fbcon.c

@@ -2243,7 +2243,7 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
 	return 0;
 }
 
-static int fbcon_debug_enter(struct vc_data *vc)
+static void fbcon_debug_enter(struct vc_data *vc)
 {
 	struct fb_info *info = fbcon_info_from_console(vc->vc_num);
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -2253,10 +2253,9 @@ static int fbcon_debug_enter(struct vc_data *vc)
 	if (info->fbops->fb_debug_enter)
 		info->fbops->fb_debug_enter(info);
 	fbcon_set_palette(vc, color_table);
-	return 0;
 }
 
-static int fbcon_debug_leave(struct vc_data *vc)
+static void fbcon_debug_leave(struct vc_data *vc)
 {
 	struct fb_info *info = fbcon_info_from_console(vc->vc_num);
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -2264,7 +2263,6 @@ static int fbcon_debug_leave(struct vc_data *vc)
 	ops->graphics = ops->save_graphics;
 	if (info->fbops->fb_debug_leave)
 		info->fbops->fb_debug_leave(info);
-	return 0;
 }
 
 static int fbcon_get_font(struct vc_data *vc, struct console_font *font, unsigned int vpitch)

include/linux/console.h

@@ -88,11 +88,11 @@ struct consw {
 	 * limited to, unblanking the console, loading an appropriate
 	 * palette, and allowing debugger generated output.
 	 */
-	int	(*con_debug_enter)(struct vc_data *vc);
+	void	(*con_debug_enter)(struct vc_data *vc);
 	/*
 	 * Restore the console to its pre-debug state as closely as possible.
 	 */
-	int	(*con_debug_leave)(struct vc_data *vc);
+	void	(*con_debug_leave)(struct vc_data *vc);
 };
 
 extern const struct consw *conswitchp;
@@ -113,17 +113,11 @@ int do_unregister_con_driver(const struct consw *csw);
 int do_take_over_console(const struct consw *sw, int first, int last, int deflt);
 void give_up_console(const struct consw *sw);
 #ifdef CONFIG_HW_CONSOLE
-int con_debug_enter(struct vc_data *vc);
-int con_debug_leave(void);
+void con_debug_enter(struct vc_data *vc);
+void con_debug_leave(void);
 #else
-static inline int con_debug_enter(struct vc_data *vc)
-{
-	return 0;
-}
-static inline int con_debug_leave(void)
-{
-	return 0;
-}
+static inline void con_debug_enter(struct vc_data *vc) { }
+static inline void con_debug_leave(void) { }
 #endif
 
 /* cursor */