Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbYH2Hpe (ORCPT ); Fri, 29 Aug 2008 03:45:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751815AbYH2HpZ (ORCPT ); Fri, 29 Aug 2008 03:45:25 -0400 Received: from smtp-out003.kontent.com ([81.88.40.217]:39630 "EHLO smtp-out003.kontent.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750893AbYH2HpY (ORCPT ); Fri, 29 Aug 2008 03:45:24 -0400 From: Oliver Neukum Organization: NOvell To: stefan_kopp@agilent.com Subject: Re: [PATCH] USB: add USB test and measurement class driver - round 2 Date: Fri, 29 Aug 2008 09:46:36 +0200 User-Agent: KMail/1.9.9 Cc: korgull@home.nl, greg@kroah.com, stern@rowland.harvard.edu, linux-usb@vger.kernel.org, me@felipebalbi.com, linux-kernel@vger.kernel.org References: <20080827183615.GA15692@kroah.com> <200808281858.42486.korgull@home.nl> <7D8F552F9FFBAC438A816966BEC4516BFBA328@cos-us-mb07.cos.agilent.com> In-Reply-To: <7D8F552F9FFBAC438A816966BEC4516BFBA328@cos-us-mb07.cos.agilent.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808290946.37898.oliver@neukum.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 846 Lines: 15 Am Freitag 29 August 2008 08:57:54 schrieb stefan_kopp@agilent.com: > The issue with using cat on the shell level is that it uses fread which has the (in this case) ugly behaviour of recalling the driver's read method until the full number of characters requested has been accumulated (or until zero characters are returned, indicating the end of file). With USBTMC instruments, this behavour is bad because the retry This may be problematic. The driver is throwing away EOF in other words. Generally this is not a good idea. User space can no longer tell how long the reply was. Regards Oliver -- 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/