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 B595EC433F5 for ; Fri, 25 Feb 2022 13:26:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241286AbiBYN0m (ORCPT ); Fri, 25 Feb 2022 08:26:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240999AbiBYN0h (ORCPT ); Fri, 25 Feb 2022 08:26:37 -0500 Received: from 1wt.eu (wtarreau.pck.nerim.net [62.212.114.60]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 31A8C202890 for ; Fri, 25 Feb 2022 05:26:04 -0800 (PST) Received: (from willy@localhost) by pcw.home.local (8.15.2/8.15.2/Submit) id 21PDPfo3019237; Fri, 25 Feb 2022 14:25:41 +0100 Date: Fri, 25 Feb 2022 14:25:41 +0100 From: Willy Tarreau To: Steven Rostedt Cc: David Laight , LKML , Petr Mladek , Sergey Senozhatsky , John Ogness Subject: Re: Strange output on the console Message-ID: <20220225132541.GD18720@1wt.eu> References: <20220224230035.36547137@gandalf.local.home> <61226fc12ff9459d8daed8e346d6ab94@AcuMS.aculab.com> <20220225063637.GA18039@1wt.eu> <1dcb185901f04a5ea2476a449e371167@AcuMS.aculab.com> <20220225103239.GA18720@1wt.eu> <32a7af26f4494f47a03a6d965ac7c99a@AcuMS.aculab.com> <20220225122546.GB18720@1wt.eu> <20220225081719.7710f62e@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220225081719.7710f62e@gandalf.local.home> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 25, 2022 at 08:17:19AM -0500, Steven Rostedt wrote: > On Fri, 25 Feb 2022 13:25:46 +0100 > Willy Tarreau wrote: > > > > TnsTesOT s T sKTesOT sKTvsOTtsTtsKTtsT sKTesTesKT sKTesOT siT stTnsaTvsaTesKTnsOT s > > > TesKTnsT s TvsKTeslT sOTesT sKTtseTnseTvs_Tts_T sOTes TnsOT s T spTespTesdTesdTeseTtseTeseTt_rTe_rTv_oTes:T s:Tes:TnfwOTvfrKT fwT frTefpuTefpKTefpTvf:TnsOTvsOTnsoTvs Tvs TvsTtssTnsT sKTesTnsTvsTtsoTesmTnsgTesiTeslTtsTvsKTnsTvsOTtsT s_Tnsu > > > > > > which really doesn't have enough different characters in it to be a fifo problem. > > > That looks like a UART struggling to find valid start and stop bits > > > on a continuous data stream that doesn't match the baud rate. > > > > > > It may also be that whatever 'terminal' is being used is masking off the 0x80 bit. > > > > That could be one option I thought about but still, that sounds quite > > suspicious. You don't even get any #!:$/ etc. Or maybe the UART is > > configured in 6-bit mode (most 16550 support 5-8 bits), and maybe even > > the stop bit and/or parity participates. > > One thing that's not easy to demonstrate here (I could try to video it), is > that this output is the final result. It shows a bunch of other characters > as it is displayed but then the cursor goes backwards and writes over it. > > But the characters that are deleted still do not make sense. When watching > it, it reminds me of the Matrix characters, but running horizontal and not > vertical. Ah, so 6-bit might definitely make sense. > > ... and Steven having fun reading our proposals after having made this > > up entirely in preparation of the next April's fool :-) > > > I was thinking the same thing, but this output being the joke. Someone > planning on slipping in Matrix characters for printk? ;-) Willy