Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752829AbaGJVVD (ORCPT ); Thu, 10 Jul 2014 17:21:03 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:41437 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbaGJVVA (ORCPT ); Thu, 10 Jul 2014 17:21:00 -0400 Date: Thu, 10 Jul 2014 22:20:30 +0100 From: One Thousand Gnomes To: David Laight Cc: "'Olivier Sobrie'" , David Miller , "j.dumon@option.com" , "linux-usb@vger.kernel.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] hso: fix deadlock when receiving bursts of data Message-ID: <20140710222030.0a194b1b@alan.etchedpixels.co.uk> In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D17270187@AcuExch.aculab.com> References: <1404723967-24245-1-git-send-email-olivier@sobrie.be> <1404723967-24245-2-git-send-email-olivier@sobrie.be> <20140708.161633.2130069042930765600.davem@davemloft.net> <20140710142848.GA28056@hposo> <063D6719AE5E284EB5DD2968C1650D6D17270044@AcuExch.aculab.com> <20140710165003.0309924e@alan.etchedpixels.co.uk> <063D6719AE5E284EB5DD2968C1650D6D17270187@AcuExch.aculab.com> Organization: Intel Corporation X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.23; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > You really want to apply flow control back over the 'serial' link. > That may just cause data discards earlier on the local system. > But it is possible that not resubmitting the receive urb will cause the > modem to flow control back to the sender. > In which case there is some chance that data won't be lost. If you are doing PPP and you can't keep up the sooner you chuck data the better. Flow control actually works against performance and good network behaviour. It's counter intuitive but TCP/IP works best if any performance bottlenecks are immediately visible and not covered over. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/