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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64DAEC433DF for ; Wed, 27 May 2020 10:12:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3294E208B8 for ; Wed, 27 May 2020 10:12:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590574359; bh=FOjlm5UER4jby4rc5jYPlrHbBUjPG7n+36gIu/fnV4c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ngYmWu5pUuUk7CiGYMm1EHWuusnI5X1A20zlVT98OEbPtknVPVQUQ6FaEQ3mmCkWg sn1LaZrG1soE8bBELX2YX24WqrN7PazNBBwQSxZLro5PBmJo3R4NOJqpucHvnW6Uph tdimPHUYPi09C7iICkvVzqFMFbsLVygDL10MMkD8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387782AbgE0KMi (ORCPT ); Wed, 27 May 2020 06:12:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:56022 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387767AbgE0KMi (ORCPT ); Wed, 27 May 2020 06:12:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ACD792088E; Wed, 27 May 2020 10:12:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590574358; bh=FOjlm5UER4jby4rc5jYPlrHbBUjPG7n+36gIu/fnV4c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=L303npg+YMdfX3GEph2tXstKysYi0f0vMbQIlFaEqJojyCDX0mImY7QAnSfnrOsL5 mSnH41UUNmRhEBc7pPFDPU6rGB5La7Dp9VAirmWvcoDTc2qUSHSMqcac15hED1oRO8 Iqc5RsPnX/twIEUnWw0/dNJ8m6KUWnhxs2auxgaU= Date: Wed, 27 May 2020 12:12:36 +0200 From: Greg KH To: Joakim Tjernlund Cc: "oneukum@suse.com" , "linux-usb@vger.kernel.org" Subject: Re: ttyACM: disabled by hub (EMI?), re-enabling... Causes garbage chars & disconnect Message-ID: <20200527101236.GB281913@kroah.com> References: <1590418977.2838.16.camel@suse.com> <1590482853.2838.26.camel@suse.com> <8cf71160e703a18b28d27a844406d42f6cadf39b.camel@infinera.com> <1590488084.2838.34.camel@suse.com> <42c92312c74e90e5507de4103bd15bbbe175f98d.camel@infinera.com> <4c2bd25aa7f6672cb132487f7af6a787ffc1fab6.camel@infinera.com> <1590568683.2838.42.camel@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, May 27, 2020 at 09:40:47AM +0000, Joakim Tjernlund wrote: > On Wed, 2020-05-27 at 10:38 +0200, Oliver Neukum wrote: > > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > > > > Am Dienstag, den 26.05.2020, 17:19 +0000 schrieb Joakim Tjernlund: > > > > > > This "u-boot SPL" is the first thing u-boot writes and somehow this is remembered, I assume, by cdc_acm > > > and gets echoed back when I open ttyACM0 > > > > Hi, > > > > that makes sense, but it is not something that we could really > > change in CDC-ACM, I am afraid. > > Why not? CDC-ACM should echo back anything it has received before open of ttyACM Is that in the specification somewhere? I don't think there is any requirement, otherwise that could be a huge waste of memory, right? How many bytes do you "keep" around? thanks, greg k-h