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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 8D3B5C433DF for ; Mon, 8 Jun 2020 15:41:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 744B22078C for ; Mon, 8 Jun 2020 15:41:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730264AbgFHPlS (ORCPT ); Mon, 8 Jun 2020 11:41:18 -0400 Received: from mx2.suse.de ([195.135.220.15]:44802 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729580AbgFHPlS (ORCPT ); Mon, 8 Jun 2020 11:41:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 12DABB11D; Mon, 8 Jun 2020 15:41:21 +0000 (UTC) Message-ID: <1591630857.24937.5.camel@suse.com> Subject: Re: ttyACM: disabled by hub (EMI?), re-enabling... Causes garbage chars & disconnect From: Oliver Neukum To: Joakim Tjernlund , "linux-usb@vger.kernel.org" Date: Mon, 08 Jun 2020 17:40:57 +0200 In-Reply-To: <914176111c9eee651f402b499bc5ec49ff634e00.camel@infinera.com> References: <6a4fe396ab5ae6cda548e904c57bc823103999d7.camel@infinera.com> <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> <1590576068.2838.56.camel@suse.com> <9971e8a97ea0f9d63864829fd8f2f4db897fc131.camel@infinera.com> <1591607631.24937.3.camel@suse.com> <914176111c9eee651f402b499bc5ec49ff634e00.camel@infinera.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Am Montag, den 08.06.2020, 11:39 +0000 schrieb Joakim Tjernlund: > Most terminal programs I use tries to empty the read queue after open, just to avoid > old garbage så I don't see a problem here. It it up to the terminal app. > Maybe one could use O_DIRECT for this purpose ? Well, we can throw away stuff received until some time in open(2). But you can always have stuff in the buffer when open(2) returns. User space needs to be ready to deal with stuff in the buffer. Regards Oliver