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From: Thomas Zimmermann <tzimmermann@suse.de>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: jirislaby@kernel.org, deller@gmx.de,
	James.Bottomley@hansenpartnership.com, simona@ffwll.ch,
	linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	linux-fbdev@vger.kernel.org, linux-parisc@vger.kernel.org,
	sashiko-reviews@lists.linux.dev
Subject: Re: [PATCH 1/2] vt: Use boolean as parameter to do_blank_screen() and do_unblank_screen()
Date: Mon, 12 Oct 2026 14:41:34 +0200	[thread overview]
Message-ID: <6f774188-86ef-4a84-84c9-d8e45fa3db45@suse.de> (raw)
In-Reply-To: <1ad9f380-7efe-4323-acbc-a3cca3420184@suse.de>



Am 12.10.26 um 14:28 schrieb 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@suse.de>
>>> ---
>>>   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.

And looking even further, it's not entirely clear why consw.con_blank 
even receives the mode_switch parameter.  The consoles track it with 
some internal state, but all of the mode information is available in 
struct vc_data.vc_mode as well.  I think mode_switch and similar 
booleans could be replaced with using vc_mode directly.



-- 
--
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)



  reply	other threads:[~2026-10-12 12:41 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-12  9:27 [PATCH 0/2] vt: Simplify console-blanking interface Thomas Zimmermann
2026-10-12  9:27 ` [PATCH 1/2] vt: Use boolean as parameter to do_blank_screen() and do_unblank_screen() Thomas Zimmermann
2026-10-12 11:30   ` Greg KH
2026-10-12 12:28     ` Thomas Zimmermann
2026-10-12 12:41       ` Thomas Zimmermann [this message]
2026-10-12 16:13         ` Greg KH
2026-10-12  9:27 ` [PATCH 2/2] vt: Distinguish between blanking and VESA blank mode in con_blank Thomas Zimmermann
2026-10-12 11:29   ` Greg KH
2026-10-12 12:08     ` Thomas Zimmermann

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