From: Samuel Thibault <Samuel.Thibault@ens-lyon.fr>
Still working on kernel facilities for braille devices, the need for being
able to force blanking and unblanking raised: even when a key is pressed, the
screen must remain blank, for privacy of the blind user who is typing on the
keyboard and reading on its braille terminal.
I merely added an ignore_poke variable which is set, and the screen blanked.
Then, poke_blanked_console returns immediatly. Upon real unblank (because of
an Oops or an explicit tioclinux), ignore_poke is reset to get back to normal
operation mode.
I had to remove the (unnecessary ?) call to unblank_screen from set_selection
to prevent mouse selection unblanking the screen.
I also added a way for processes to know whether the screen is blanked (the
blind user might hence know whether people can read the screen).
25-akpm/drivers/char/selection.c | 1 -
25-akpm/drivers/char/vt.c | 18 ++++++++++++++++--
2 files changed, 16 insertions(+), 3 deletions(-)
diff -puN drivers/char/selection.c~console-privacy drivers/char/selection.c
--- 25/drivers/char/selection.c~console-privacy Tue Jun 3 13:21:33 2003
+++ 25-akpm/drivers/char/selection.c Tue Jun 3 13:21:33 2003
@@ -118,7 +118,6 @@ int set_selection(const unsigned long ar
int i, ps, pe;
unsigned int currcons = fg_console;
- unblank_screen();
poke_blanked_console();
{ unsigned short *args, xs, ys, xe, ye;
diff -puN drivers/char/vt.c~console-privacy drivers/char/vt.c
--- 25/drivers/char/vt.c~console-privacy Tue Jun 3 13:21:33 2003
+++ 25-akpm/drivers/char/vt.c Tue Jun 3 13:22:50 2003
@@ -163,6 +163,12 @@ static void console_callback(void *ignor
static int printable; /* Is console ready for printing? */
+/*
+ * ignore_poke: don't unblank the screen when things are typed. This is
+ * mainly for the privacy of braille terminal users.
+ */
+static int ignore_poke;
+
int do_poke_blanked_console;
int console_blanked;
@@ -1314,7 +1320,7 @@ static void setterm_command(int currcons
case 14: /* set vesa powerdown interval */
vesa_off_interval = ((par[1] < 60) ? par[1] : 60) * 60 * HZ;
break;
- case 15: /* Activate the previous console */
+ case 15: /* activate the previous console */
set_console(last_console);
break;
}
@@ -2282,6 +2288,13 @@ int tioclinux(struct tty_struct *tty, un
ret = 0;
}
break;
+ case 14: /* blank screen until explicitly unblanked, not only poked */
+ ignore_poke = 1;
+ do_blank_screen(0);
+ break;
+ case 15: /* which console is blanked ? */
+ ret = console_blanked;
+ break;
default:
ret = -EINVAL;
break;
@@ -2753,6 +2766,7 @@ void unblank_screen(void)
{
int currcons;
+ ignore_poke = 0;
if (!console_blanked)
return;
if (!vc_cons_allocated(fg_console)) {
@@ -2790,7 +2804,7 @@ static void blank_screen(unsigned long d
void poke_blanked_console(void)
{
del_timer(&console_timer);
- if (!vt_cons[fg_console] || vt_cons[fg_console]->vc_mode == KD_GRAPHICS)
+ if (ignore_poke || !vt_cons[fg_console] || vt_cons[fg_console]->vc_mode == KD_GRAPHICS)
return;
if (console_blanked) {
console_timer.function = unblank_screen_t;
_