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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7C09EC433E0 for ; Mon, 22 Feb 2021 12:10:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BFB164E05 for ; Mon, 22 Feb 2021 12:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230153AbhBVMKo (ORCPT ); Mon, 22 Feb 2021 07:10:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:56192 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230090AbhBVMKc (ORCPT ); Mon, 22 Feb 2021 07:10:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1613995783; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yLeSjdAn6ytvvSZ7l1bruf6v0eYDWUB2oiRB+v/1EnM=; b=e/nAV+MYeJjAgiyPTwc40OITAzxjyTJR6GKilTsxVYuBh8sK8jo7wYdB+AV3weQEJR4YWY hZ3CT15WUxeCSGnV7dmKjSzHJx4w88Ebamntg49TLET0SNTdnFQFE3G4pHu6cTJbJv4N10 aTyCPn+8FaTPp1cVYwCPRJ4lpv4xDYY= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1FB54AD5C; Mon, 22 Feb 2021 12:09:43 +0000 (UTC) Message-ID: Subject: Re: [PATCH] usbnet: ipheth: fix connectivity with iOS 14 From: Oliver Neukum To: Sam Bingner , "linux-usb@vger.kernel.org" Cc: "David S. Miller" , Martin Habets , Luc Van Oostenryck , Shannon Nelson , "Michael S. Tsirkin" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Matti Vuorela , Jakub Kicinski , Yves-Alexis Perez Date: Mon, 22 Feb 2021 13:09:38 +0100 In-Reply-To: <370902e520c44890a44cb5dd0cb1595f@bingner.com> References: <370902e520c44890a44cb5dd0cb1595f@bingner.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Sonntag, den 21.02.2021, 10:42 +0000 schrieb Sam Bingner: > There seems to be a problem with this patch: > > Whenever the iPhone sends a packet to the tethered device that is 1500 bytes long, it gets the error "ipheth 1-1:4.2: ipheth_rcvbulk_callback: urb status: -79" on the connected device and stops passing traffic. I am able to bring it back up by shutting and unshutting the interface, but the same thing happens very quickly. I noticed that this patch dropped the max USB packet size from 1516 to 1514 bytes, so I decided to try lowering the MTU to 1498; this made the connection reliable and no more errors occurred. > > It appears to me that the iPhone is still sending out 1516 bytes over USB for a 1500 byte packet and this patch makes USB abort when that happens? I could duplicate reliably by sending a ping from the iphone (ping -s 1472) to the connected device, or vice versa as the reply would then break it. > > I apologize if this reply doesn't end up where it should - I tried to reply to the last message in this thread but I wasn't actually *on* the thread so I had to just build it as much as possible myself. Is this a regression? Does it work after reverting the patch? Which version of iOS? Regards Oliver