From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 5 Jan 2001 20:50:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 5 Jan 2001 20:50:04 -0500 Received: from smtp3.libero.it ([193.70.192.53]:42389 "EHLO smtp3.libero.it") by vger.kernel.org with ESMTP id ; Fri, 5 Jan 2001 20:49:56 -0500 Date: Sat, 6 Jan 2001 04:50:50 +0100 From: antirez To: "Dunlap, Randy" Cc: "'antirez@invece.org'" , Greg KH , Heitzso , "'linux-kernel@vger.kernel.org'" , "'Johannes Erdfelt'" Subject: Re: USB broken in 2.4.0 Message-ID: <20010106045050.C1748@prosa.it> Reply-To: antirez@invece.org In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from randy.dunlap@intel.com on Fri, Jan 05, 2001 at 04:48:00PM -0800 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 05, 2001 at 04:48:00PM -0800, Dunlap, Randy wrote: > This rings a small bell with me. > There was a change by Dan Streetman IIRC to limit > usbdevfs bulk transfers to PAGE_SIZE (4 KB for x86, > or 0x1000). Anything larger than that returns > an error (-EINVAL). Yes, devio.c, proc_bulk(): if (len1 > PAGE_SIZE) return -EINVAL; Actually it is the max transfer size I can reach. I guess that to limit the page size can be an impementation advantage but it may slow-down a bit some userspace driver. I feel that even if the linux way is to implement the USB drivers in kernel space a full-featured USB user space access should be allowed. antirez (please cc me) -- Salvatore Sanfilippo | http://www.kyuzz.org/antirez | PGP: finger antirez@tella.alicom.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/