linux-kernel - Re: [PATCH] vt: Add enable module parameter

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Message-ID: <48be84fb-bee4-4a22-bde4-0d0c78282f80@redhat.com>
Date: Mon, 26 Jan 2026 10:43:35 +0100
From: Jocelyn Falempe <jfalempe@...hat.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Jiri Slaby <jirislaby@...nel.org>, Nicolas Pitre <npitre@...libre.com>,
 Calixte Pernot <calixte.pernot@...noble-inp.org>,
 linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org
Subject: Re: [PATCH] vt: Add enable module parameter

On 26/01/2026 10:33, Greg Kroah-Hartman wrote:
> On Mon, Jan 26, 2026 at 10:21:50AM +0100, Jocelyn Falempe wrote:
>> This allows to build the kernel with CONFIG_VT enabled, and choose
>> on the kernel command line to enable it or not.
> 
> This says what is happening, but not why?
> 
>> Add vt.enable=1 to force enable, or vt.enable=0 to force disable.
> 
> Why are we using a 1990's technology for a new feature?  What is this
> going to allow to have happen?  Who needs/wants this?  Who will use it?
> For what?

The goal is to ease the transition to disable CONFIG_VT.

So if this is merged, you can boot without VT on any Linux distribution, 
without rebuilding the kernel.

This option will also allow a distribution to disable VT by default, but 
users that really wants this can enable it on the kernel command line, 
without rebuilding the kernel.

It will also avoid hacky solution in userspace like this:
https://overhead.neocities.org/blog/systemd-logind-seat/#very-hacky-solutions


> 
>> Signed-off-by: Jocelyn Falempe <jfalempe@...hat.com>
>> ---
>>   drivers/tty/Kconfig | 13 +++++++++++++
>>   drivers/tty/vt/vt.c |  5 +++++
>>   2 files changed, 18 insertions(+)
>>
>> diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
>> index 149f3d53b7608..2b94c2710687a 100644
>> --- a/drivers/tty/Kconfig
>> +++ b/drivers/tty/Kconfig
>> @@ -41,6 +41,19 @@ config VT
>>   	  If unsure, say Y, or else you won't be able to do much with your new
>>   	  shiny Linux system :-)
>>   
>> +config VT_ENABLE
>> +	depends on VT
>> +	default y
>> +	bool "enable VT terminal" if EXPERT
> 
> So no one will ever really use this config option?
> 
> And you are doing 2 things in this patch, not just one, unlike what the
> changelog said :(

I can split that in two if you prefer.

Adding a module parameter, and adding a Kconfig option, to choose the 
default for this module parameter.

> 
> thanks,
> 
> greg k-h
> 

-- 

Jocelyn