Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750816AbVJNRqK (ORCPT ); Fri, 14 Oct 2005 13:46:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750817AbVJNRqK (ORCPT ); Fri, 14 Oct 2005 13:46:10 -0400 Received: from john.hrz.tu-chemnitz.de ([134.109.132.2]:27067 "EHLO john.hrz.tu-chemnitz.de") by vger.kernel.org with ESMTP id S1750816AbVJNRqI (ORCPT ); Fri, 14 Oct 2005 13:46:08 -0400 To: Greg KH Cc: Chris Wright , kernel-stuff@comcast.net, stable@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [stable] Re: [PATCH] Re: bug in handling of highspeed usb HID devices References: <101320051953.12930.434EBB460007F30B0000328222007589429D0E050B9A9D0E99@comcast.net> <20051013212518.GY5856@shell0.pdx.osdl.net> <20051014171326.GA16496@kroah.com> From: Christian Krause Date: Fri, 14 Oct 2005 19:46:02 +0200 In-Reply-To: <20051014171326.GA16496@kroah.com> (Greg KH's message of "Fri, 14 Oct 2005 10:13:26 -0700") Message-ID: User-Agent: Gnus/5.1006 (Gnus v5.10.6) XEmacs/21.4 (Jumbo Shrimp, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Spam-Score: 0.0 (/) X-Spam-Report: --- Start der SpamAssassin 3.1.0 Textanalyse (0.0 Punkte) Fragen an/questions to: Postmaster TU Chemnitz --- Ende der SpamAssassin Textanalyse X-Scan-Signature: a37c3661e0372786d6c154dc38711565 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1671 Lines: 41 On Fri, 14 Oct 2005 10:13:26 -0700, Greg KH wrote: > On Thu, Oct 13, 2005 at 02:25:18PM -0700, Chris Wright wrote: >> * kernel-stuff@comcast.net (kernel-stuff@comcast.net) wrote: >> > This seems to be -stable material since it's a clear cut bug with bad >> > consequences. >> > >> > Chris Wright - is the below patch acceptable for -stable? > Also, I don't think this should go into -stable, as there are no > high-speed HID devices available right now, so it really isn't affecting > anyone :) No, that's no correct. There are such devices: Newer KVM-over-IP appliances, like the Avocent's DSR2030 emulates keyboard, mouse and a mass storage device over USB. I've tested this specific device with linux and the USB transfers are Highspeed and the USB device has one interface which is HID. So there are Highspeed USB devices out there. With all respect, but I don't really understand why this is important. The linux kernel clearly violates the USB specification. The calculation of the real polling interval for interrupt endpoints is i = 2^(bInterval-1) (according to USB 2.0 spec, chapter 9.6.6) and _not_ i = 2^((2^(bInterval-1))-1) as it is calculated in linux. This is clearly a bug in linux and should be fixed. Changing this has _no_ impact on other devices than Highspeed HID devices and only this patch allows them to work. And there are such devices. At least Avocent's DSR2030. Best regards, Christian - 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/