From owner-freebsd-usb@FreeBSD.ORG Fri Aug 19 23:40:12 2005 Return-Path: X-Original-To: freebsd-usb@freebsd.org Delivered-To: freebsd-usb@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4B5DD16A420 for ; Fri, 19 Aug 2005 23:40:12 +0000 (GMT) (envelope-from brian@aljex.com) Received: from s1tank.virtdom.com (s1tank.virtdom.com [216.240.101.50]) by mx1.FreeBSD.org (Postfix) with SMTP id A424043D46 for ; Fri, 19 Aug 2005 23:40:11 +0000 (GMT) (envelope-from brian@aljex.com) Received: (qmail 9378 invoked by uid 89); 19 Aug 2005 23:59:28 -0000 Received: from ool-43552092.dyn.optonline.net (HELO venti) (brian@aljex.com@67.85.32.146) by s1tank.virtdom.com with SMTP; 19 Aug 2005 23:59:28 -0000 Message-ID: <027101c5a517$5573a400$6b00000a@venti> From: "Brian K. White" To: References: <6f896f9a05081915315fc8f82d@mail.gmail.com> Date: Fri, 19 Aug 2005 19:39:14 -0400 Organization: Aljex Software MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Subject: Re: Drivers in kernel of user space? 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, 19 Aug 2005 23:40:12 -0000 ----- Original Message ----- From: "Karolis Tamutis" To: Sent: Friday, August 19, 2005 6:31 PM Subject: Drivers in kernel of user space? Should drivers for an usb device (or a series of devices) be developed in kernel space or in user space, now that we have such cross platform ported libraries as libusb? What's your opinion. ------------------- Isn't there problems with libusb that make it a big compromize ? For example, last I knew (admittedly several months ago) the reason my canoscan lide scanner was so horrendously slow in linux was because it used libusb and libusb didn't have a way to do the type of transfer the scanner really needs. Something about async vs sync? I know in freebsd I have used the same scanner both using the in-kernel /dev/uscanner0, and libusb. I didn't do these things at the same time or on the same machine, nor had I yet tried to do a high quality scan that exposed the slowness compared to the same scan in windows. So I never tried a direct comparison of speeds under the different drivers on the same hardware doing the same scan. Been meaning to since the scanner happens to be on a freebsd box again and I have uses for the scanner again. Brian K. White -- brian@aljex.com -- http://www.aljex.com/bkw/ +++++[>+++[>+++++>+++++++<<-]<-]>>+.>.+++++.+++++++.-.[>+<---]>++. filePro BBx Linux SCO FreeBSD #callahans Satriani Filk!