[PATCH 6.6 058/139] tty: vt: make init parameter of consw::con_init() a bool

[PATCH 6.6 058/139] tty: vt: make init parameter of consw::con_init() a bool

[Greg Kroah-Hartman]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby (SUSE) <jirislaby@kernel.org>

[ Upstream commit dae3e6b6180f1a2394b984c596d39ed2c57d25fe ]

The 'init' parameter of consw::con_init() is true for the first call of
the hook on a particular console. So make the parameter a bool.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-21-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 03bcbbb3995b ("dummycon: Trigger redraw when switching consoles with deferred takeover")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/vt/vt.c                 | 8 ++++----
 drivers/video/console/dummycon.c    | 2 +-
 drivers/video/console/mdacon.c      | 2 +-
 drivers/video/console/newport_con.c | 2 +-
 drivers/video/console/sticon.c      | 2 +-
 drivers/video/console/vgacon.c      | 4 ++--
 drivers/video/fbdev/core/fbcon.c    | 2 +-
 include/linux/console.h             | 4 +++-
 8 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 6bd1a7785e888..83028ccf6e529 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -999,7 +999,7 @@ int vc_cons_allocated(unsigned int i)
 	return (i < MAX_NR_CONSOLES && vc_cons[i].d);
 }
 
-static void visual_init(struct vc_data *vc, int num, int init)
+static void visual_init(struct vc_data *vc, int num, bool init)
 {
 	/* ++Geert: vc->vc_sw->con_init determines console size */
 	if (vc->vc_sw)
@@ -1083,7 +1083,7 @@ int vc_allocate(unsigned int currcons)	/* return 0 on success */
 	vc->port.ops = &vc_port_ops;
 	INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 
-	visual_init(vc, currcons, 1);
+	visual_init(vc, currcons, true);
 
 	if (!*vc->uni_pagedict_loc)
 		con_set_default_unimap(vc);
@@ -3474,7 +3474,7 @@ static int __init con_init(void)
 		vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
 		INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
 		tty_port_init(&vc->port);
-		visual_init(vc, currcons, 1);
+		visual_init(vc, currcons, true);
 		/* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
 		vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
 		vc_init(vc, currcons || !vc->vc_sw->con_save_screen);
@@ -3642,7 +3642,7 @@ static int do_bind_con_driver(const struct consw *csw, int first, int last,
 		old_was_color = vc->vc_can_do_color;
 		vc->vc_sw->con_deinit(vc);
 		vc->vc_origin = (unsigned long)vc->vc_screenbuf;
-		visual_init(vc, i, 0);
+		visual_init(vc, i, false);
 		set_origin(vc);
 		update_attr(vc);
 
diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index f1711b2f9ff05..9a19eb72a18b9 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -97,7 +97,7 @@ static const char *dummycon_startup(void)
     return "dummy device";
 }
 
-static void dummycon_init(struct vc_data *vc, int init)
+static void dummycon_init(struct vc_data *vc, bool init)
 {
     vc->vc_can_do_color = 1;
     if (init) {
diff --git a/drivers/video/console/mdacon.c b/drivers/video/console/mdacon.c
index ef29b321967f0..c5b255c968794 100644
--- a/drivers/video/console/mdacon.c
+++ b/drivers/video/console/mdacon.c
@@ -352,7 +352,7 @@ static const char *mdacon_startup(void)
 	return "MDA-2";
 }
 
-static void mdacon_init(struct vc_data *c, int init)
+static void mdacon_init(struct vc_data *c, bool init)
 {
 	c->vc_complement_mask = 0x0800;	 /* reverse video */
 	c->vc_display_fg = &mda_display_fg;
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index e8e4f82cd4a1b..12c64ef470877 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -324,7 +324,7 @@ static const char *newport_startup(void)
 	return NULL;
 }
 
-static void newport_init(struct vc_data *vc, int init)
+static void newport_init(struct vc_data *vc, bool init)
 {
 	int cols, rows;
 
diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index 992a4fa431aaa..0bfeabc3f7c72 100644
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -273,7 +273,7 @@ static int sticon_font_set(struct vc_data *vc, struct console_font *font,
 	return sticon_set_font(vc, font, vpitch);
 }
 
-static void sticon_init(struct vc_data *c, int init)
+static void sticon_init(struct vc_data *c, bool init)
 {
     struct sti_struct *sti = sticon_sti;
     int vc_cols, vc_rows;
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index c9ec89649b055..490e157aebdd4 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -332,7 +332,7 @@ static const char *vgacon_startup(void)
 	return display_desc;
 }
 
-static void vgacon_init(struct vc_data *c, int init)
+static void vgacon_init(struct vc_data *c, bool init)
 {
 	struct uni_pagedict *p;
 
@@ -349,7 +349,7 @@ static void vgacon_init(struct vc_data *c, int init)
 	c->vc_scan_lines = vga_scan_lines;
 	c->vc_font.height = c->vc_cell_height = vga_video_font_height;
 
-	/* set dimensions manually if init != 0 since vc_resize() will fail */
+	/* set dimensions manually if init is true since vc_resize() will fail */
 	if (init) {
 		c->vc_cols = vga_video_num_columns;
 		c->vc_rows = vga_video_num_lines;
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 75996ef9992e4..9f10a6e92e509 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -993,7 +993,7 @@ static const char *fbcon_startup(void)
 	return display_desc;
 }
 
-static void fbcon_init(struct vc_data *vc, int init)
+static void fbcon_init(struct vc_data *vc, bool init)
 {
 	struct fb_info *info;
 	struct fbcon_ops *ops;
diff --git a/include/linux/console.h b/include/linux/console.h
index 7de11c763eb35..4efe76ac56d74 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -36,6 +36,8 @@ enum vc_intensity;
 /**
  * struct consw - callbacks for consoles
  *
+ * @con_init:   initialize the console on @vc. @init is true for the very first
+ *		call on this @vc.
  * @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
  *		Return true if no generic handling should be done.
  *		Invoked by csi_M and printing to the console.
@@ -46,7 +48,7 @@ enum vc_intensity;
 struct consw {
 	struct module *owner;
 	const char *(*con_startup)(void);
-	void	(*con_init)(struct vc_data *vc, int init);
+	void	(*con_init)(struct vc_data *vc, bool init);
 	void	(*con_deinit)(struct vc_data *vc);
 	void	(*con_clear)(struct vc_data *vc, int sy, int sx, int height,
 			int width);
-- 
2.39.5

[PATCH 6.6 059/139] tty: vt: sanitize arguments of consw::con_clear()

[Greg Kroah-Hartman]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby (SUSE) <jirislaby@kernel.org>

[ Upstream commit 559f01a0ee6d924c6fec3eaf6a5b078b15e71070 ]

In consw::con_clear():
* Height is always 1, so drop it.
* Offsets and width are always unsigned values, so re-type them as such.

This needs a new __fbcon_clear() in the fbcon code to still handle
height which might not be 1 when called internally.

Note that tests for negative count/width are left in place -- they are
taken care of in the next patches.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-22-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 03bcbbb3995b ("dummycon: Trigger redraw when switching consoles with deferred takeover")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/vt/vt.c                 |  2 +-
 drivers/video/console/dummycon.c    |  4 ++--
 drivers/video/console/mdacon.c      | 15 +++++---------
 drivers/video/console/newport_con.c |  6 +++---
 drivers/video/console/sticon.c      |  8 ++++----
 drivers/video/console/vgacon.c      |  4 ++--
 drivers/video/fbdev/core/fbcon.c    | 32 +++++++++++++++++------------
 include/linux/console.h             |  5 +++--
 8 files changed, 39 insertions(+), 37 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 83028ccf6e529..a368c98c92be3 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -1582,7 +1582,7 @@ static void csi_X(struct vc_data *vc, unsigned int vpar)
 	vc_uniscr_clear_line(vc, vc->state.x, count);
 	scr_memsetw((unsigned short *)vc->vc_pos, vc->vc_video_erase_char, 2 * count);
 	if (con_should_update(vc))
-		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, 1, count);
+		vc->vc_sw->con_clear(vc, vc->state.y, vc->state.x, count);
 	vc->vc_need_wrap = 0;
 }
 
diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index 9a19eb72a18b9..6918014b02408 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -108,8 +108,8 @@ static void dummycon_init(struct vc_data *vc, bool init)
 }
 
 static void dummycon_deinit(struct vc_data *vc) { }
-static void dummycon_clear(struct vc_data *vc, int sy, int sx, int height,
-			   int width) { }
+static void dummycon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+			   unsigned int width) { }
 static void dummycon_cursor(struct vc_data *vc, int mode) { }
 
 static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
diff --git a/drivers/video/console/mdacon.c b/drivers/video/console/mdacon.c
index c5b255c968794..1ddbb6cd5b0ca 100644
--- a/drivers/video/console/mdacon.c
+++ b/drivers/video/console/mdacon.c
@@ -442,23 +442,18 @@ static void mdacon_putcs(struct vc_data *c, const unsigned short *s,
 	}
 }
 
-static void mdacon_clear(struct vc_data *c, int y, int x, 
-			  int height, int width)
+static void mdacon_clear(struct vc_data *c, unsigned int y, unsigned int x,
+			 unsigned int width)
 {
 	u16 *dest = mda_addr(x, y);
 	u16 eattr = mda_convert_attr(c->vc_video_erase_char);
 
-	if (width <= 0 || height <= 0)
+	if (width <= 0)
 		return;
 
-	if (x==0 && width==mda_num_columns) {
-		scr_memsetw(dest, eattr, height*width*2);
-	} else {
-		for (; height > 0; height--, dest+=mda_num_columns)
-			scr_memsetw(dest, eattr, width*2);
-	}
+	scr_memsetw(dest, eattr, width * 2);
 }
-                        
+
 static int mdacon_switch(struct vc_data *c)
 {
 	return 1;	/* redrawing needed */
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 12c64ef470877..55c6106b3507b 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -346,12 +346,12 @@ static void newport_deinit(struct vc_data *c)
 	}
 }
 
-static void newport_clear(struct vc_data *vc, int sy, int sx, int height,
-			  int width)
+static void newport_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+			  unsigned int width)
 {
 	int xend = ((sx + width) << 3) - 1;
 	int ystart = ((sy << 4) + topscan) & 0x3ff;
-	int yend = (((sy + height) << 4) + topscan - 1) & 0x3ff;
+	int yend = (((sy + 1) << 4) + topscan - 1) & 0x3ff;
 
 	if (logo_active)
 		return;
diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index 0bfeabc3f7c72..d99c2a659bfd4 100644
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -300,13 +300,13 @@ static void sticon_deinit(struct vc_data *c)
 	sticon_set_def_font(i);
 }
 
-static void sticon_clear(struct vc_data *conp, int sy, int sx, int height,
-			 int width)
+static void sticon_clear(struct vc_data *conp, unsigned int sy, unsigned int sx,
+			 unsigned int width)
 {
-    if (!height || !width)
+    if (!width)
 	return;
 
-    sti_clear(sticon_sti, sy, sx, height, width,
+    sti_clear(sticon_sti, sy, sx, 1, width,
 	      conp->vc_video_erase_char, font_data[conp->vc_num]);
 }
 
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 490e157aebdd4..5b5d1c9ef488c 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1156,8 +1156,8 @@ static bool vgacon_scroll(struct vc_data *c, unsigned int t, unsigned int b,
  *  The console `switch' structure for the VGA based console
  */
 
-static void vgacon_clear(struct vc_data *vc, int sy, int sx, int height,
-			 int width) { }
+static void vgacon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+			 unsigned int width) { }
 static void vgacon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
 static void vgacon_putcs(struct vc_data *vc, const unsigned short *s,
 			 int count, int ypos, int xpos) { }
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index 9f10a6e92e509..c14dbb09341fc 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -1240,8 +1240,8 @@ static void fbcon_deinit(struct vc_data *vc)
  *  restriction is simplicity & efficiency at the moment.
  */
 
-static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
-			int width)
+static void __fbcon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+			  unsigned int height, unsigned int width)
 {
 	struct fb_info *info = fbcon_info_from_console(vc->vc_num);
 	struct fbcon_ops *ops = info->fbcon_par;
@@ -1280,6 +1280,12 @@ static void fbcon_clear(struct vc_data *vc, int sy, int sx, int height,
 		ops->clear(vc, info, real_y(p, sy), sx, height, width, fg, bg);
 }
 
+static void fbcon_clear(struct vc_data *vc, unsigned int sy, unsigned int sx,
+			unsigned int width)
+{
+	__fbcon_clear(vc, sy, sx, 1, width);
+}
+
 static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
 			int count, int ypos, int xpos)
 {
@@ -1767,7 +1773,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 		case SCROLL_MOVE:
 			fbcon_redraw_blit(vc, info, p, t, b - t - count,
 				     count);
-			fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
 			scr_memsetw((unsigned short *) (vc->vc_origin +
 							vc->vc_size_row *
 							(b - count)),
@@ -1790,7 +1796,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 					    b - t - count, vc->vc_cols);
 			else
 				goto redraw_up;
-			fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_PAN_REDRAW:
@@ -1808,7 +1814,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 							  vc->vc_rows - b, b);
 			} else
 				fbcon_redraw_move(vc, p, t + count, b - t - count, t);
-			fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_PAN_MOVE:
@@ -1831,14 +1837,14 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 					    b - t - count, vc->vc_cols);
 			else
 				goto redraw_up;
-			fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_REDRAW:
 		      redraw_up:
 			fbcon_redraw(vc, t, b - t - count,
 				     count * vc->vc_cols);
-			fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, b - count, 0, count, vc->vc_cols);
 			scr_memsetw((unsigned short *) (vc->vc_origin +
 							vc->vc_size_row *
 							(b - count)),
@@ -1855,7 +1861,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 		case SCROLL_MOVE:
 			fbcon_redraw_blit(vc, info, p, b - 1, b - t - count,
 				     -count);
-			fbcon_clear(vc, t, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, t, 0, count, vc->vc_cols);
 			scr_memsetw((unsigned short *) (vc->vc_origin +
 							vc->vc_size_row *
 							t),
@@ -1878,7 +1884,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 					    b - t - count, vc->vc_cols);
 			else
 				goto redraw_down;
-			fbcon_clear(vc, t, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, t, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_PAN_MOVE:
@@ -1900,7 +1906,7 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 					    b - t - count, vc->vc_cols);
 			else
 				goto redraw_down;
-			fbcon_clear(vc, t, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, t, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_PAN_REDRAW:
@@ -1917,14 +1923,14 @@ static bool fbcon_scroll(struct vc_data *vc, unsigned int t, unsigned int b,
 					fbcon_redraw_move(vc, p, count, t, 0);
 			} else
 				fbcon_redraw_move(vc, p, t, b - t - count, t + count);
-			fbcon_clear(vc, t, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, t, 0, count, vc->vc_cols);
 			break;
 
 		case SCROLL_REDRAW:
 		      redraw_down:
 			fbcon_redraw(vc, b - 1, b - t - count,
 				     -count * vc->vc_cols);
-			fbcon_clear(vc, t, 0, count, vc->vc_cols);
+			__fbcon_clear(vc, t, 0, count, vc->vc_cols);
 			scr_memsetw((unsigned short *) (vc->vc_origin +
 							vc->vc_size_row *
 							t),
@@ -2203,7 +2209,7 @@ static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
 
 		oldc = vc->vc_video_erase_char;
 		vc->vc_video_erase_char &= charmask;
-		fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
+		__fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
 		vc->vc_video_erase_char = oldc;
 	}
 }
diff --git a/include/linux/console.h b/include/linux/console.h
index 4efe76ac56d74..e06cee4923fef 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -38,6 +38,7 @@ enum vc_intensity;
  *
  * @con_init:   initialize the console on @vc. @init is true for the very first
  *		call on this @vc.
+ * @con_clear:  erase @count characters at [@x, @y] on @vc. @count >= 1.
  * @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
  *		Return true if no generic handling should be done.
  *		Invoked by csi_M and printing to the console.
@@ -50,8 +51,8 @@ struct consw {
 	const char *(*con_startup)(void);
 	void	(*con_init)(struct vc_data *vc, bool init);
 	void	(*con_deinit)(struct vc_data *vc);
-	void	(*con_clear)(struct vc_data *vc, int sy, int sx, int height,
-			int width);
+	void	(*con_clear)(struct vc_data *vc, unsigned int y,
+			     unsigned int x, unsigned int count);
 	void	(*con_putc)(struct vc_data *vc, int c, int ypos, int xpos);
 	void	(*con_putcs)(struct vc_data *vc, const unsigned short *s,
 			int count, int ypos, int xpos);
-- 
2.39.5

[PATCH 6.6 060/139] tty: vt: make consw::con_switch() return a bool

[Greg Kroah-Hartman]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby (SUSE) <jirislaby@kernel.org>

[ Upstream commit 8d5cc8eed738e3202379722295c626cba0849785 ]

The non-zero (true) return value from consw::con_switch() means a redraw
is needed. So make this return type a bool explicitly instead of int.
The latter might imply that -Eerrors are expected. They are not.

And document the hook.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-parisc@vger.kernel.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-31-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 03bcbbb3995b ("dummycon: Trigger redraw when switching consoles with deferred takeover")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/vt/vt.c                 | 2 +-
 drivers/video/console/dummycon.c    | 4 ++--
 drivers/video/console/mdacon.c      | 4 ++--
 drivers/video/console/newport_con.c | 4 ++--
 drivers/video/console/sticon.c      | 4 ++--
 drivers/video/console/vgacon.c      | 4 ++--
 drivers/video/fbdev/core/fbcon.c    | 6 +++---
 include/linux/console.h             | 4 +++-
 8 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index a368c98c92be3..c5ec7306aa713 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -962,7 +962,7 @@ void redraw_screen(struct vc_data *vc, int is_switch)
 	}
 
 	if (redraw) {
-		int update;
+		bool update;
 		int old_was_color = vc->vc_can_do_color;
 
 		set_origin(vc);
diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index 6918014b02408..d701f2b51f5b1 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -119,9 +119,9 @@ static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
 	return false;
 }
 
-static int dummycon_switch(struct vc_data *vc)
+static bool dummycon_switch(struct vc_data *vc)
 {
-	return 0;
+	return false;
 }
 
 /*
diff --git a/drivers/video/console/mdacon.c b/drivers/video/console/mdacon.c
index 1ddbb6cd5b0ca..26b41a8f36c87 100644
--- a/drivers/video/console/mdacon.c
+++ b/drivers/video/console/mdacon.c
@@ -454,9 +454,9 @@ static void mdacon_clear(struct vc_data *c, unsigned int y, unsigned int x,
 	scr_memsetw(dest, eattr, width * 2);
 }
 
-static int mdacon_switch(struct vc_data *c)
+static bool mdacon_switch(struct vc_data *c)
 {
-	return 1;	/* redrawing needed */
+	return true;	/* redrawing needed */
 }
 
 static int mdacon_blank(struct vc_data *c, int blank, int mode_switch)
diff --git a/drivers/video/console/newport_con.c b/drivers/video/console/newport_con.c
index 55c6106b3507b..63d96c4bbdccd 100644
--- a/drivers/video/console/newport_con.c
+++ b/drivers/video/console/newport_con.c
@@ -462,7 +462,7 @@ static void newport_cursor(struct vc_data *vc, int mode)
 	}
 }
 
-static int newport_switch(struct vc_data *vc)
+static bool newport_switch(struct vc_data *vc)
 {
 	static int logo_drawn = 0;
 
@@ -476,7 +476,7 @@ static int newport_switch(struct vc_data *vc)
 		}
 	}
 
-	return 1;
+	return true;
 }
 
 static int newport_blank(struct vc_data *c, int blank, int mode_switch)
diff --git a/drivers/video/console/sticon.c b/drivers/video/console/sticon.c
index d99c2a659bfd4..87900600eff11 100644
--- a/drivers/video/console/sticon.c
+++ b/drivers/video/console/sticon.c
@@ -310,9 +310,9 @@ static void sticon_clear(struct vc_data *conp, unsigned int sy, unsigned int sx,
 	      conp->vc_video_erase_char, font_data[conp->vc_num]);
 }
 
-static int sticon_switch(struct vc_data *conp)
+static bool sticon_switch(struct vc_data *conp)
 {
-    return 1;	/* needs refreshing */
+    return true;	/* needs refreshing */
 }
 
 static int sticon_blank(struct vc_data *c, int blank, int mode_switch)
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 5b5d1c9ef488c..bbc362db40c58 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -585,7 +585,7 @@ static void vgacon_doresize(struct vc_data *c,
 	raw_spin_unlock_irqrestore(&vga_lock, flags);
 }
 
-static int vgacon_switch(struct vc_data *c)
+static bool vgacon_switch(struct vc_data *c)
 {
 	int x = c->vc_cols * VGA_FONTWIDTH;
 	int y = c->vc_rows * c->vc_cell_height;
@@ -614,7 +614,7 @@ static int vgacon_switch(struct vc_data *c)
 			vgacon_doresize(c, c->vc_cols, c->vc_rows);
 	}
 
-	return 0;		/* Redrawing not needed */
+	return false;		/* Redrawing not needed */
 }
 
 static void vga_set_palette(struct vc_data *vc, const unsigned char *table)
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index c14dbb09341fc..9d095fe03e18b 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -2072,7 +2072,7 @@ static int fbcon_resize(struct vc_data *vc, unsigned int width,
 	return 0;
 }
 
-static int fbcon_switch(struct vc_data *vc)
+static bool fbcon_switch(struct vc_data *vc)
 {
 	struct fb_info *info, *old_info = NULL;
 	struct fbcon_ops *ops;
@@ -2194,9 +2194,9 @@ static int fbcon_switch(struct vc_data *vc)
 			      vc->vc_origin + vc->vc_size_row * vc->vc_top,
 			      vc->vc_size_row * (vc->vc_bottom -
 						 vc->vc_top) / 2);
-		return 0;
+		return false;
 	}
-	return 1;
+	return true;
 }
 
 static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
diff --git a/include/linux/console.h b/include/linux/console.h
index e06cee4923fef..38571607065d7 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -42,6 +42,8 @@ enum vc_intensity;
  * @con_scroll: move lines from @top to @bottom in direction @dir by @lines.
  *		Return true if no generic handling should be done.
  *		Invoked by csi_M and printing to the console.
+ * @con_switch: notifier about the console switch; it is supposed to return
+ *		true if a redraw is needed.
  * @con_set_palette: sets the palette of the console to @table (optional)
  * @con_scrolldelta: the contents of the console should be scrolled by @lines.
  *		     Invoked by user. (optional)
@@ -60,7 +62,7 @@ struct consw {
 	bool	(*con_scroll)(struct vc_data *vc, unsigned int top,
 			unsigned int bottom, enum con_scroll dir,
 			unsigned int lines);
-	int	(*con_switch)(struct vc_data *vc);
+	bool	(*con_switch)(struct vc_data *vc);
 	int	(*con_blank)(struct vc_data *vc, int blank, int mode_switch);
 	int	(*con_font_set)(struct vc_data *vc, struct console_font *font,
 			unsigned int vpitch, unsigned int flags);
-- 
2.39.5

[PATCH 6.6 061/139] dummycon: Trigger redraw when switching consoles with deferred takeover

[Greg Kroah-Hartman]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Zimmermann <tzimmermann@suse.de>

[ Upstream commit 03bcbbb3995ba5df43af9aba45334e35f2dfe27b ]

Signal vt subsystem to redraw console when switching to dummycon
with deferred takeover enabled. Makes the console switch to fbcon
and displays the available output.

With deferred takeover enabled, dummycon acts as the placeholder
until the first output to the console happens. At that point, fbcon
takes over. If the output happens while dummycon is not active, it
cannot inform fbcon. This is the case if the vt subsystem runs in
graphics mode.

A typical graphical boot starts plymouth, a display manager and a
compositor; all while leaving out dummycon. Switching to a text-mode
console leaves the console with dummycon even if a getty terminal
has been started.

Returning true from dummycon's con_switch helper signals the vt
subsystem to redraw the screen. If there's output available dummycon's
con_putc{s} helpers trigger deferred takeover of fbcon, which sets a
display mode and displays the output. If no output is available,
dummycon remains active.

v2:
- make the comment slightly more verbose (Javier)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reported-by: Andrei Borzenkov <arvidjaar@gmail.com>
Closes: https://bugzilla.suse.com/show_bug.cgi?id=1242191
Tested-by: Andrei Borzenkov <arvidjaar@gmail.com>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Fixes: 83d83bebf401 ("console/fbcon: Add support for deferred console takeover")
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.19+
Link: https://lore.kernel.org/r/20250520071418.8462-1-tzimmermann@suse.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/console/dummycon.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index d701f2b51f5b1..d99e1b3e4e5c1 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -82,6 +82,15 @@ static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
 	/* Redraw, so that we get putc(s) for output done while blanked */
 	return 1;
 }
+
+static bool dummycon_switch(struct vc_data *vc)
+{
+	/*
+	 * Redraw, so that we get putc(s) for output done while switched
+	 * away. Informs deferred consoles to take over the display.
+	 */
+	return true;
+}
 #else
 static void dummycon_putc(struct vc_data *vc, int c, int ypos, int xpos) { }
 static void dummycon_putcs(struct vc_data *vc, const unsigned short *s,
@@ -90,6 +99,10 @@ static int dummycon_blank(struct vc_data *vc, int blank, int mode_switch)
 {
 	return 0;
 }
+static bool dummycon_switch(struct vc_data *vc)
+{
+	return false;
+}
 #endif
 
 static const char *dummycon_startup(void)
@@ -119,11 +132,6 @@ static bool dummycon_scroll(struct vc_data *vc, unsigned int top,
 	return false;
 }
 
-static bool dummycon_switch(struct vc_data *vc)
-{
-	return false;
-}
-
 /*
  *  The console `switch' structure for the dummy console
  *
-- 
2.39.5