It is already possible to deactivate the vc bell on a per-tty basis,

by using echo -en "\e[11;0]", but this is reset on reset(1).
This adds a sysfs parameter to globally control the vc bell, as well

as sysfs parameters for default pitch and duration.
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
---

 drivers/char/vt.c |   18 +++++++++++-------

 1 file changed, 11 insertions(+), 7 deletions(-)
Index: linux-2.6.23/drivers/char/vt.c

===================================================================

--- linux-2.6.23.orig/drivers/char/vt.c

+++ linux-2.6.23/drivers/char/vt.c

@@ -134,8 +134,12 @@ const struct consw *conswitchp;

 /*

  * Here is the default bell parameters: 750HZ, 1/8th of a second

  */

-#define DEFAULT_BELL_PITCH	750

-#define DEFAULT_BELL_DURATION	(HZ/8)

+static unsigned int default_bell_pitch = 750;

+static unsigned int default_bell_duration = HZ / 8;

+static unsigned int vc_bell_enabled = true;

+module_param_named(bell_pitch, default_bell_pitch, uint, S_IRUGO | S_IWUSR);

+module_param_named(bell_duration, default_bell_duration, uint, S_IRUGO | S_IWUSR);

+module_param_named(bell_enabled, vc_bell_enabled, uint, S_IRUGO | S_IWUSR);
 struct vc vc_cons [MAX_NR_CONSOLES];
@@ -1401,14 +1405,14 @@ static void setterm_command(struct vc_da

 			if (vc->vc_npar >= 1)

 				vc->vc_bell_pitch = vc->vc_par[1];

 			else

-				vc->vc_bell_pitch = DEFAULT_BELL_PITCH;

+				vc->vc_bell_pitch = default_bell_pitch;

 			break;

 		case 11: /* set bell duration in msec */

 			if (vc->vc_npar >= 1)

 				vc->vc_bell_duration = (vc->vc_par[1] < 2000) ?

 					vc->vc_par[1] * HZ / 1000 : 0;

 			else

-				vc->vc_bell_duration = DEFAULT_BELL_DURATION;

+				vc->vc_bell_duration = default_bell_duration;

 			break;

 		case 12: /* bring specified console to the front */

 			if (vc->vc_par[1] >= 1 && vc_cons_allocated(vc->vc_par[1] - 1))

@@ -1554,8 +1558,8 @@ static void reset_terminal(struct vc_dat

 	vc->vc_tab_s...
[ message continues ]

There are more parameters that should be set during reset... like

cursor size and color, palette, .... What about /sys/.../string_to_interpret

_on_reset ?

							Pavel
--

(english) http://www.livejournal.com/~pavelmachek

(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

-

On reset(1), cursor size, palette, and bell parameters _do_ get reset

to the defaults. Some defaults may already be changed by the user,

like palette or default_utf8.
Bell configuration is currently not one of them so, should a program

decide to reset the tty, or should it happen that your output is

garbled (forcing you to do reset), some settings change back to

"unwanted defaults".

-

Ok, and I'm suggesting general method for the "unwanted defaults"

problem. Just have a /sys/.../terminal_init_string.
During reset, let console code interpret terminal_init_string, to set

_wanted_ defaults. So you'd do:
echo -en "\e[11;0]" > /sys/.../terminal_init_string... and I'd do

something similar with softcursor settings. (Which are currently reset

to compiled-in defaults, and that is "unwanted defaults" to me).

								Pavel

--

(english) http://www.livejournal.com/~pavelmachek

(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

-

On Fri, 5 Oct 2007 13:55:52 +0200 (CEST)
Why do we need this?  To fix the stupid-app-makes-my-box-beep problem, I

guess.  Is there no other way of suppressing the beep? (no jokes about wire
It is inapt to call these default_X.  Because once they have been altered

by the user, they aren't defaults any more.
They should be just bell_pitch and bell_duration.
-

The user has a number of choices:

- rmmod pcspkr, to disable all beeps (including X)

- vt.bell_enabled=0, to disable beeps on all VCs, but not X

- vt.default_bell_pitch=400, to give VC the frequency used in X
They are still default, as in: they will define the initial

pitch/duration when a tty is created, or when the tty is reset.
If they were just 'bell_pitch', one culd assume that changing it

changes the pitch of all ttys, which it does not. Whether it's good

or not that the vc subsytem has per-tty pitches is a different story.
Well, that's what I am thinking about it.

-

On Fri, 5 Oct 2007 17:00:11 -0700
man setterm
See -blength and -bfreq
Alan

-

Only sets length and freq of current tty, and only until `reset`.

It's equivalent to \e[10;x] and \e[11;x].

-