[PATCH] [RESEND] fbcon: simple text blinking implementation

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Hi all,
at the moment blinking is not supported in fbcon but it is supported in
vgacon.
Since userspace applications don't distinguish between the two, they just
assume that the linux terminal is always capable of blinking text.
However implementing blinking in fbcon is not so difficult: this patch
provides a very simple (too simple?) implementation of that.
I am using the flashcursor function to scan the buffer for blinking text.
For the sake of efficiency I added a simple flag mechanism to disable the scan
when I am sure that there are no blinking characters on the screen.

Signed-off-by: stefano.stabellini@eu.citrix.com

---
 drivers/video/console/fbcon.c |   62 +++++++++++++++++++++++++++++++++-------
 1 files changed, 51 insertions(+), 11 deletions(-)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 97aff8d..163b37a 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -152,6 +152,8 @@ static int fbcon_has_sysfs;
 
 static const struct consw fb_con;
 
+static int blink_flag = 1;
+
 #define CM_SOFTBACK	(8)
 
 #define advance_row(p, delta) (unsigned short *)((unsigned long)(p) + (delta) * vc->vc_size_row)
@@ -402,24 +404,58 @@ static void fb_flashcursor(struct work_struct *work)
 	struct vc_data *vc = NULL;
 	int c;
 	int mode;
+	unsigned short *s;
+	int x = 0, y = 0;
+	static int show_blink = 1;
 
 	acquire_console_sem();
 	if (ops && ops->currcon != -1)
 		vc = vc_cons[ops->currcon].d;
 
 	if (!vc || !CON_IS_VISIBLE(vc) ||
- 	    registered_fb[con2fb_map[vc->vc_num]] != info ||
-	    vc->vc_deccm != 1) {
+	    registered_fb[con2fb_map[vc->vc_num]] != info) {
 		release_console_sem();
 		return;
 	}
 
 	p = &fb_display[vc->vc_num];
-	c = scr_readw((u16 *) vc->vc_pos);
-	mode = (!ops->cursor_flash || ops->cursor_state.enable) ?
-		CM_ERASE : CM_DRAW;
-	ops->cursor(vc, info, mode, softback_lines, get_color(vc, info, c, 1),
-		    get_color(vc, info, c, 0));
+	if (vc->vc_deccm == 1 && !(vc->vc_cursor_type & 0x10)) {
+		c = scr_readw((u16 *) vc->vc_pos);
+		mode = (!ops->cursor_flash || ops->cursor_state.enable) ?
+			CM_ERASE : CM_DRAW;
+		ops->cursor(vc, info, mode, softback_lines,
+				get_color(vc, info, c, 1),
+				get_color(vc, info, c, 0));
+	}
+
+	if (vc->vc_hi_font_mask || !blink_flag) {
+		release_console_sem();
+		return;
+	}
+	if (!softback_lines)
+		s = (u16 *) vc->vc_origin;
+	else
+		s = (u16 *) softback_curr;
+	while (y < vc->vc_rows) {
+		while (x < vc->vc_cols) {
+			c = scr_readw(s);
+			if (attr_blink(c)) {
+				blink_flag = 1;
+				if (!show_blink)
+					c = (c & 0xf4ff) | (attr_bgcol(12, c) << 8);
+				fbcon_putc(vc, c, y, x);
+			}
+			s++;
+			x++;
+		}
+		x = 0;
+		y++;
+		if (s == (u16 *) softback_end)
+			s = (u16 *) softback_buf;
+		if (s == (u16 *) softback_in)
+			s = (u16 *) vc->vc_origin;
+	}
+	show_blink = show_blink ? 0 : 1;
 	release_console_sem();
 }
 
@@ -1331,6 +1367,8 @@ static void fbcon_putcs(struct vc_data *vc, const unsigned short *s,
 	struct display *p = &fb_display[vc->vc_num];
 	struct fbcon_ops *ops = info->fbcon_par;
 
+	if (!vc->vc_hi_font_mask && (vc->vc_attr & 0x80))
+		blink_flag = 1;
 	if (!fbcon_is_inactive(vc, info))
 		ops->putcs(vc, info, s, count, real_y(p, ypos), xpos,
 			   get_color(vc, info, scr_readw(s), 1),
@@ -1350,6 +1388,7 @@ static void fbcon_clear_margins(struct vc_data *vc, int bottom_only)
 	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
 	struct fbcon_ops *ops = info->fbcon_par;
 
+	blink_flag = 1;
 	if (!fbcon_is_inactive(vc, info))
 		ops->clear_margins(vc, info, bottom_only);
 }
@@ -1364,10 +1403,7 @@ static void fbcon_cursor(struct vc_data *vc, int mode)
 	if (fbcon_is_inactive(vc, info) || vc->vc_deccm != 1)
 		return;
 
-	if (vc->vc_cursor_type & 0x10)
-		fbcon_del_cursor_timer(info);
-	else
-		fbcon_add_cursor_timer(info);
+	fbcon_add_cursor_timer(info);
 
 	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;
 	if (mode & CM_SOFTBACK) {
@@ -1860,6 +1896,7 @@ static int fbcon_scroll(struct vc_data *vc, int t, int b, int dir,
 		return -EINVAL;
 
 	fbcon_cursor(vc, CM_ERASE);
+	blink_flag = 1;
 
 	/*
 	 * ++Geert: Only use ywrap/ypan if the console is in text mode
@@ -2074,6 +2111,8 @@ static void fbcon_bmove(struct vc_data *vc, int sy, int sx, int dy, int dx,
 	if (!width || !height)
 		return;
 
+	blink_flag = 1;
+
 	/*  Split blits that cross physical y_wrap case.
 	 *  Pathological case involves 4 blits, better to use recursive
 	 *  code rather than unrolled case
@@ -2811,6 +2850,7 @@ static int fbcon_scrolldelta(struct vc_data *vc, int lines)
 	struct display *disp = &fb_display[fg_console];
 	int offset, limit, scrollback_old;
 
+	blink_flag = 1;
 	if (softback_top) {
 		if (vc->vc_num != fg_console)
 			return 0;