From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 310A93370E5; Mon, 26 Jan 2026 12:46:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769431577; cv=none; b=pbUjn2TSOBF51K4IzjT6MgUa3cOGst7E5i2ymv89rJxpXa8jDWCNJJBWeJB/na36Y8/mwx8CfLBSFPRCG9Q3yff7CWBJuMXn/C/TxbHo2v0+AaM/0j2v2KiQv2AHF/JKtxLiLmRYehtJV8U66ncfXlrYODrE9Wda+3cDU4ZrqV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769431577; c=relaxed/simple; bh=k18hCT2YpytEknYRaduTylJOgowbaIZE4KZSXA/VR18=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kzA8ka/eiZSgEToe4S++5CpQAYJonAc4cbMP5SOtLVSOju/ONa0LvSBWJ9rojqnJFdnaJ30syS4punAzRFe6Uel2MW3swpoqg1PDUSlZbOdkjqUQ4X6mDvEXdYSjkdqLcfpb3Zg1k4YBvM2aV9FNdZC5NFP/Fi2lgbnDgOfsTzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zulG9fyy; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zulG9fyy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E019C2BC86; Mon, 26 Jan 2026 12:46:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769431576; bh=k18hCT2YpytEknYRaduTylJOgowbaIZE4KZSXA/VR18=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=zulG9fyyzWdwTf51ApuMhC0r25/NqTYV9r3ebym2GbML+3uS8heB9Y/SuGzYngAZP 75g4R1tmXEQLuO3mb5eKgf4cFniVq2W94KWiBnRsFyT7ni5VmNBA6avZatDUGwx5Lq yKs5mMiN+zg0T2ecA/2bn+LYAuC97fdPOMNbsKwM= Date: Mon, 26 Jan 2026 13:46:13 +0100 From: Greg Kroah-Hartman To: Jocelyn Falempe Cc: Jiri Slaby , Nicolas Pitre , Calixte Pernot , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH] vt: Add enable module parameter Message-ID: <2026012653-designer-capably-d575@gregkh> References: <20260126092234.713465-1-jfalempe@redhat.com> <2026012613-cotton-jellied-b67a@gregkh> <48be84fb-bee4-4a22-bde4-0d0c78282f80@redhat.com> <2026012648-vantage-mummified-2a43@gregkh> <45526d98-57b6-456e-babc-61b7331318c0@redhat.com> <2026012642-threefold-atypical-a3ad@gregkh> <99371939-e9b2-4114-8e27-e605ebf941de@redhat.com> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <99371939-e9b2-4114-8e27-e605ebf941de@redhat.com> On Mon, Jan 26, 2026 at 01:26:34PM +0100, Jocelyn Falempe wrote: > On 26/01/2026 11:59, Greg Kroah-Hartman wrote: > > On Mon, Jan 26, 2026 at 11:48:50AM +0100, Jocelyn Falempe wrote: > > > On 26/01/2026 11:20, Greg Kroah-Hartman wrote: > > > > On Mon, Jan 26, 2026 at 10:43:35AM +0100, Jocelyn Falempe wrote: > > > > > 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. > > > > > > > > But that's a distro-specific thing, the distro should be enabling or > > > > disabling the option as it needs, it should not be a user-configurable > > > > boot-time selection option as userspace depends entirely on this either > > > > being there or not. Why would you have a kernel with both options but > > > > userspace without that? > > > > > > Actually the userspace side works with or without VT, at least with Fedora, > > > I've my Gnome session in both cases. > > > > Great! Then why is this even needed? Who wants such a "let's not make > > up our mind until we boot" type of system? > > > > Given that traditionally the command line is a "secure" thing, that is > > locked down by distros and orginizations, who would ever be able to be > > changing this type of thing? Who would want to support userspace that > > handles both at the same time? > > > > I don't see the issue here, if a distro doesn't want to support VT, then > > disable it in the kernel and all is good. If they do want to support > > it, than enable it. Don't do both :) > > Maybe the real issue is that VT cannot be built as a module. > That way the userspace would be able to load it only if it needs it. > > That's probably more complex than my 3 lines patch, but I can try. > Would you prefer it that way? If that would make it simpler for a distro to handle this, perhaps. Try it and see, I think the last time this came up, unwinding this into a module just wasn't possible, but that might have been a long time ago, I can't recall. But again, why wouldn't a distro pick a "this is what we are going to support" line and stick with it? Why would they want to support both? thanks, greg k-h