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 076E4C4332F for ; Mon, 30 Oct 2023 14:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233592AbjJ3OUC (ORCPT ); Mon, 30 Oct 2023 10:20:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233469AbjJ3OUA (ORCPT ); Mon, 30 Oct 2023 10:20:00 -0400 Received: from netrider.rowland.org (netrider.rowland.org [192.131.102.5]) by lindbergh.monkeyblade.net (Postfix) with SMTP id 09AE0C0 for ; Mon, 30 Oct 2023 07:19:55 -0700 (PDT) Received: (qmail 672852 invoked by uid 1000); 30 Oct 2023 10:19:54 -0400 Date: Mon, 30 Oct 2023 10:19:54 -0400 From: Alan Stern To: Greg KH Cc: ariel marcovitch , johan@kernel.org, linux-usb@vger.kernel.org, Linux Kernel Mailing List Subject: Re: Gaps in logs while using usb-serial as a console Message-ID: <968c62ca-0ef2-4bf1-a17b-a6d88d5e2e20@rowland.harvard.edu> References: <2023103052-unpeeled-calibrate-ae48@gregkh> <2023103003-defection-recess-cf49@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2023103003-defection-recess-cf49@gregkh> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 30, 2023 at 09:30:15AM +0100, Greg KH wrote: > On Mon, Oct 30, 2023 at 10:15:30AM +0200, ariel marcovitch wrote: > > > Please realize that usb-serial console was the result of me loosing a > > > drunken bet. It's amazing it works at all. For "fake" devices like > > LOL your drunken bet was quite helpful to some people > > Because modern PCs come without a serial port, I wanted to use it to > > see early logs on my crashing kernel without having to use printk > > delay and things like that. > > I'm curious as to how kernel people debug PCs in general... > > We use a usb debug port connection (it's a special cable). Sometimes people use netconsole (see Documentation/networking/netconsole.rst). I don't know how common it is nowadays, and it may not be quite as reliable as a debug port device, but it should still work. And it doesn't require special hardware. Alan Stern