From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753419Ab1I0Kvx (ORCPT ); Tue, 27 Sep 2011 06:51:53 -0400 Received: from mga02.intel.com ([134.134.136.20]:10498 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751843Ab1I0Kvv (ORCPT ); Tue, 27 Sep 2011 06:51:51 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,351,1309762800"; d="scan'208";a="56987860" Date: Tue, 27 Sep 2011 11:59:57 +0100 From: Alan Cox To: Mikhail Kshevetskiy Cc: linux-serial@vger.kernel.org, gregkh@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output Message-ID: <20110927115957.5e6cb79c@bob.linux.org.uk> In-Reply-To: <1316791376-4863-2-git-send-email-mikhail.kshevetskiy@gmail.com> References: <1316791376-4863-1-git-send-email-mikhail.kshevetskiy@gmail.com> <1316791376-4863-2-git-send-email-mikhail.kshevetskiy@gmail.com> Organization: Intel X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; x86_64-redhat-linux-gnu) Organisation: Intel Corporation UK Ltd, registered no. 1134945 (England), Registered office Pipers Way, Swindon, SN3 1RJ 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 On Fri, 23 Sep 2011 19:22:56 +0400 Mikhail Kshevetskiy wrote: > n_gsm use a simple approach: every writing to fifo correspond exactly > one reading from fifo. There are no problem in this approach until we > read less bytes then we write. As result fifo may owerflow. This > leads to packet loss and very slow responce. We do need to do something here but your change means a single DLCI will hog the channel, so I think the while loop needs to be one layer up. Alan