[PATCH] fbcon: Cursor fixes

From Jiri Benc:

we found several bugs in framebuffer console code in recent kernels.

1. The escape sequence '\033[?25l' does not work (should disable cursor).

2. When scrolling console using Shift-PgUp with cursor in the upper half
   part of the screen, cursor position is not updated.

3. If cursor is placed at some character and console is scrolled using
   Shift-PgUp, that character remains on the screen.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/video/console/bitblit.c

@@ -236,7 +236,7 @@ static void bit_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void bit_cursor(struct vc_data *vc, struct fb_info *info,
-		       struct display *p, int mode, int fg, int bg)
+		       struct display *p, int mode, int softback_lines, int fg, int bg)
 {
 	struct fb_cursor cursor;
 	struct fbcon_ops *ops = (struct fbcon_ops *) info->fbcon_par;
@@ -248,6 +248,15 @@ static void bit_cursor(struct vc_data *vc, struct fb_info *info,
 
 	cursor.set = 0;
 
+	if (softback_lines) {
+		if (y + softback_lines >= vc->vc_rows) {
+			mode = CM_ERASE;
+			ops->cursor_flash = 0;
+			return;
+		} else
+			y += softback_lines;
+	}
+
  	c = scr_readw((u16 *) vc->vc_pos);
 	attribute = get_attribute(info, c);
 	src = vc->vc_font.data + ((c & charmask) * (w * vc->vc_font.height));

drivers/video/console/fbcon.c

@@ -279,7 +279,7 @@ static void fb_flashcursor(void *private)
 	c = scr_readw((u16 *) vc->vc_pos);
 	mode = (!ops->cursor_flash || ops->cursor_state.enable) ?
 		CM_ERASE : CM_DRAW;
-	ops->cursor(vc, info, p, mode, get_color(vc, info, c, 1),
+	ops->cursor(vc, info, p, mode, softback_lines, get_color(vc, info, c, 1),
 		    get_color(vc, info, c, 0));
 	release_console_sem();
 }
@@ -1086,27 +1086,23 @@ static void fbcon_cursor(struct vc_data *vc, int mode)
 	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
 	struct fbcon_ops *ops = info->fbcon_par;
 	struct display *p = &fb_display[vc->vc_num];
-	int y = real_y(p, vc->vc_y);
+	int y;
  	int c = scr_readw((u16 *) vc->vc_pos);
 
 	if (fbcon_is_inactive(vc, info))
 		return;
 
-	ops->cursor_flash = 1;
+	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
 	if (mode & CM_SOFTBACK) {
 		mode &= ~CM_SOFTBACK;
-		if (softback_lines) {
-			if (y + softback_lines >= vc->vc_rows) {
-				mode = CM_ERASE;
-				ops->cursor_flash = 0;
-			}
-			else
-				y += softback_lines;
-		}
-	} else if (softback_lines)
-		fbcon_set_origin(vc);
+		y = softback_lines;
+	} else {
+		if (softback_lines)
+			fbcon_set_origin(vc);
+		y = 0;
+	}
 
-	ops->cursor(vc, info, p, mode, get_color(vc, info, c, 1),
+	ops->cursor(vc, info, p, mode, y, get_color(vc, info, c, 1),
 		    get_color(vc, info, c, 0));
 	vbl_cursor_cnt = CURSOR_DRAW_DELAY;
 }

drivers/video/console/fbcon.h

@@ -59,7 +59,7 @@ struct fbcon_ops {
 	void (*clear_margins)(struct vc_data *vc, struct fb_info *info,
 			      int bottom_only);
 	void (*cursor)(struct vc_data *vc, struct fb_info *info,
-		       struct display *p, int mode, int fg, int bg);
+		       struct display *p, int mode, int softback_lines, int fg, int bg);
 
 	struct timer_list cursor_timer; /* Cursor timer */
 	struct fb_cursor cursor_state;

drivers/video/console/tileblit.c

@@ -81,7 +81,8 @@ static void tile_clear_margins(struct vc_data *vc, struct fb_info *info,
 }
 
 static void tile_cursor(struct vc_data *vc, struct fb_info *info,
-			struct display *p, int mode, int fg, int bg)
+			struct display *p, int mode, int softback_lines,
+			int fg, int bg)
 {
 	struct fb_tilecursor cursor;
 	int use_sw = (vc->vc_cursor_type & 0x01);