VT notifier fix for VT switch

VT notifier fix for VT switch

[Samuel Thibault]

Notify when VT switch is complete.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

--- linux-2.6.24-orig/drivers/char/vt.c	2008-01-25 09:32:06.000000000 +0100
+++ linux-2.6.24-perso/drivers/char/vt.c	2008-02-21 15:51:13.000000000 +0100
@@ -702,6 +702,7 @@
 	if (is_switch) {
 		set_leds();
 		compute_shiftstate();
+		notify_update(vc);
 	}
 }
 

Re: VT notifier fix for VT switch

[Andrew Morton]

On Thu, 21 Feb 2008 21:26:40 +0100 Samuel Thibault <samuel.thibault@ens-lyon.org> wrote:

> Notify when VT switch is complete.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> 
> --- linux-2.6.24-orig/drivers/char/vt.c	2008-01-25 09:32:06.000000000 +0100
> +++ linux-2.6.24-perso/drivers/char/vt.c	2008-02-21 15:51:13.000000000 +0100
> @@ -702,6 +702,7 @@
>  	if (is_switch) {
>  		set_leds();
>  		compute_shiftstate();
> +		notify_update(vc);
>  	}
>  }
>  

The changelog is too terse, sorry.  What is the reason for making this
change?  What are the user-visible effects of not having this change?  If
it fixes a bug, should it be backported to 2.6.24.x and earlier?

etcetera.

Re: VT notifier fix for VT switch

[Samuel Thibault]

Andrew Morton, le Sat 23 Feb 2008 00:04:30 -0800, a écrit :
> On Thu, 21 Feb 2008 21:26:40 +0100 Samuel Thibault <samuel.thibault@ens-lyon.org> wrote:
> 
> > Notify when VT switch is complete.
> > 
> > Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> > 
> > --- linux-2.6.24-orig/drivers/char/vt.c	2008-01-25 09:32:06.000000000 +0100
> > +++ linux-2.6.24-perso/drivers/char/vt.c	2008-02-21 15:51:13.000000000 +0100
> > @@ -702,6 +702,7 @@
> >  	if (is_switch) {
> >  		set_leds();
> >  		compute_shiftstate();
> > +		notify_update(vc);
> >  	}
> >  }
> >  
> 
> The changelog is too terse, sorry.  What is the reason for making this
> change?  What are the user-visible effects of not having this change?

Ok:

VT notifier callbacks need to be aware of console switches.  This
is already partially done from console_callback(), but at that time
fg_console, cursor positions, etc. are not yet updated and hence screen
readers fetch the old values.

This adds an update notify after all of the values are updated in
redraw_screen(vc, 1).

> If it fixes a bug, should it be backported to 2.6.24.x and earlier?

It would be useful to backport it to 2.6.24.x indeed.  Earlier versions
don't have VT notifiers.

Samuel