From owner-freebsd-usb@FreeBSD.ORG Fri Apr 20 14:06:07 2012 Return-Path: Delivered-To: freebsd-usb@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 4425E1065672 for ; Fri, 20 Apr 2012 14:06:07 +0000 (UTC) (envelope-from hselasky@c2i.net) Received: from swip.net (mailfe09.c2i.net [212.247.155.2]) by mx1.freebsd.org (Postfix) with ESMTP id C05048FC17 for ; Fri, 20 Apr 2012 14:06:06 +0000 (UTC) X-T2-Spam-Status: No, hits=0.5 required=5.0 tests=ALL_TRUSTED, BAYES_60 Received: from [176.74.212.201] (account mc467741@c2i.net HELO laptop002.hselasky.homeunix.org) by mailfe09.swip.net (CommuniGate Pro SMTP 5.4.4) with ESMTPA id 90781327; Fri, 20 Apr 2012 16:05:58 +0200 From: Hans Petter Selasky To: freebsd-usb@freebsd.org Date: Fri, 20 Apr 2012 16:04:58 +0200 User-Agent: KMail/1.13.5 (FreeBSD/8.3-PRERELEASE; KDE/4.4.5; amd64; ; ) References: <4F9068DE.9090807@rawbw.com> In-Reply-To: <4F9068DE.9090807@rawbw.com> X-Face: 'mmZ:T{)),Oru^0c+/}w'`gU1$ubmG?lp!=R4Wy\ELYo2)@'UZ24N@d2+AyewRX}mAm; Yp |U[@, _z/([?1bCfM{_"B<.J>mICJCHAzzGHI{y7{%JVz%R~yJHIji`y>Y}k1C4TfysrsUI -%GU9V5]iUZF&nRn9mJ'?&>O MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201204201604.58751.hselasky@c2i.net> Cc: Subject: Re: usbdump(8) question X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Apr 2012 14:06:07 -0000 On Thursday 19 April 2012 21:34:54 Yuri wrote: > I am trying to use usbdump(8) on one webcam, but the produced, log > causes some questions. > Hi, > 1. Why -s 1024 option doesn't show actual data even though SLEN for > packets is non-zero? The -s option must be set bigger than the maximum total data in a USB transfer, else you will only get parts of the data. Typical value: 65536 > 2. When I run webcamd, first 4 lines of log (with the error) quickly > appear. Webcamd exits quickly, in 0.035s, but usbdump after 1-2 secs > shows the rest of the log. Why is this significant delay? Why the first > 4 lines aren't delayed? Because usbdump uses a big buffer, which is only returned when it is filled up or when a 1 second timeout triggers. --HPS