From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 968CAC64ED6 for ; Sun, 26 Feb 2023 19:59:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229764AbjBZT7K (ORCPT ); Sun, 26 Feb 2023 14:59:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229688AbjBZT7J (ORCPT ); Sun, 26 Feb 2023 14:59:09 -0500 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0388216889 for ; Sun, 26 Feb 2023 11:59:07 -0800 (PST) Received: from cwcc.thunk.org (pool-173-48-120-46.bstnma.fios.verizon.net [173.48.120.46]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 31QJwibP008362 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 26 Feb 2023 14:58:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1677441529; bh=sUDNujaHfUqZ8bjP9HuWhvva7+VEbIW3Zww8AIVTgtQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=U0g3nrxbwhModARiSgwYYoCAvHxED2XBpVYNdpkDDmekIh5GDte8nIxUPQ7pxRpvV eOjL1IS5x0OGFkKHLEJ8+9Ulestd3B1qoSgNWhr4rPMebY/HSSrLL/daGMlV7Jce3d Mjh1daVESQQKWgP2gXOaNChOupoLGbcbKV1EZXFt0oRkvktTfqq2e+OHqKYOVt5hH8 KHlmc1rZN7C8/yyK4WzAo1rLkfVuocqWNsUk1M8aMh4LZ+WhVfC8gA8QRRspQZUAKo /S4gu9XivmDxj3ishPxE+7hpRRO7VoZCikWs1TprbQ/qN2JEDbjNTt2RfBUpjte+Ws xLstb0dU2FXhQ== Received: by cwcc.thunk.org (Postfix, from userid 15806) id A014315C5823; Sun, 26 Feb 2023 14:58:44 -0500 (EST) Date: Sun, 26 Feb 2023 14:58:44 -0500 From: "Theodore Ts'o" To: Linus Torvalds Cc: Greg KH , Tharun Kumar P , Kumaravel Thiagarajan , Andy Shevchenko , Jiri Slaby , Stephen Rothwell , Andrew Morton , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [GIT PULL] TTY/Serial driver updates for 6.3-rc1 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Sat, Feb 25, 2023 at 06:14:11PM -0800, Linus Torvalds wrote: > On Sat, Feb 25, 2023 at 3:40 PM Theodore Ts'o wrote: > > > > For what it's worth, in the VM world (e.g., qemu, AWS, GCP, Azure, > > Linode, etc.) serial consoles are quite common way of debugging VM's, > > and as an emergency login path when the networking has been screwed up > > for some reason.... > > Everybody seems to be missing the point. > > We don't make new drivers "default y" (or, in this case, "default SERIAL_8250". > > It does not matter ONE WHIT if you have a serial device in your > machine. If your old driver was enabled and worked for you and you > used it daily, that is ENTIRELY IMMATERIAL to a new driver, even if > that new driver then happens to use some of the same infrastructure as > the old one did. Oh, agreed, I wasn't responding to that part of your message. New serial drivers should never be enabled by default. I was responding to your musing about whether it still made sense to enable the COM1/2/3/4 serial ports by default on x86. It's true that on desktops COM1/2/3/4 serial ports are rarely used, and some other boards might not even have them any more. But for x86 VM's, they are used quite a lot. Cheers, - Ted