Re: [PATCH 1/2] vt: Use boolean as parameter to do_blank_screen() and do_unblank_screen()

[Thomas Zimmermann]

Hi

Am 12.10.26 um 13:30 schrieb Greg KH:
> On Mon, Oct 12, 2026 at 11:27:38AM +0200, Thomas Zimmermann wrote:
> > The parameters to do_blank_screen() and do_unblank_screen() signal
> > whether the call is part of a switch between text and graphics mode.
> > Convert to boolean. No functional changes.
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > ---
> >   drivers/tty/vt/vt.c              | 20 ++++++++++----------
> >   drivers/tty/vt/vt_ioctl.c        | 12 ++++++------
> >   drivers/video/fbdev/core/fbcon.c |  4 ++--
> >   include/linux/vt_kern.h          |  5 +++--
> >   4 files changed, 21 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> > index 57edf37495a8..9e7b4419b422 100644
> > --- a/drivers/tty/vt/vt.c
> > +++ b/drivers/tty/vt/vt.c
> > @@ -3374,7 +3374,7 @@ static void console_callback(struct work_struct *ignored)
> >   		scrollback_delta = 0;
> >   	}
> >   	if (blank_timer_expired) {
> > -		do_blank_screen(0);
> > +		do_blank_screen(false);
> Same type of comment here, this bool doesn't really tell what is
> happening at all (not your fault, 0/1 doesn't either.)
>
> I'm all for this patch but shouldn't this be fixed up to be 2 different
> named functions entirely?

Can you elaborate?  Do you mean there should be a separate helper and 
callback for switching between KD_TEXT and KD_GRAPHICS?

Looking through the *_blank_screen() helpers and the console 
implementations, I think we'd mostly duplicate code. Mode-switching and 
blanking are tightly coupled.  Semantics get a bit cleaner with the 
change you proposed to patch 1, I think.

Or, we'd have to untangle all of it. The result would likely look 
something like this:

vt_set_mode(kd_mode)
{
    if (kd_mode == GRAPHICS)
        do_blank_screen() /* blank before going to graphics */

    consw->con_setmode(kd_mode)

    if (kd_mode != GRAPHICS)
        do_unblank_screen() /* unblank after coming back from graphics */
}

Best regards
Thomas


> thanks,
>
> greg k-h

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Stefan Gaiser, Jochen Jaser, Abhinav Puri, (HRB 36809, AG Nürnberg)