From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261630AbULUVJY (ORCPT ); Tue, 21 Dec 2004 16:09:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261697AbULUVJY (ORCPT ); Tue, 21 Dec 2004 16:09:24 -0500 Received: from mx1.redhat.com ([66.187.233.31]:42194 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S261630AbULUVJT (ORCPT ); Tue, 21 Dec 2004 16:09:19 -0500 Date: Tue, 21 Dec 2004 13:09:17 -0800 From: Pete Zaitcev To: Lee Revell , zaitcev@redhat.com Cc: linux-kernel@vger.kernel.org Subject: Re: Basic UB q Message-ID: <20041221130917.692d07e3@lembas.zaitcev.lan> In-Reply-To: References: Organization: Red Hat, Inc. X-Mailer: Sylpheed-Claws 0.9.12cvs126.2 (GTK+ 2.4.14; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 20 Dec 2004 16:30:57 -0500, Lee Revell wrote: > On Mon, 2004-12-20 at 22:26 +0100, Jan Engelhardt wrote: > > what is the "ub" driver good for? Doesnot USB over SCSI work well enough? > Because that requires the SCSI layer which is overkill for very simple > devices. This is not quite what I had in mind. Memory is not that expensive, and ub has to carry a miniature SCSI stack in it anyway. But getting rid of a few oopses and lockups would be nice. James does a very good job trying to contain the complexity of the SCSI stack, however I still see some problems. Perhaps not even him, not Doug Ledford, not anyone is capable of making a SCSI stack which does not crash. The 2.6.9 was especially painful and hurt us quite a bit, I'm going to be sore for a while. I cannot be sure that this sort of thing is not going to happen when we try to ship RHEL 5. But even if nothing else, I think ub is prompting some positive changes in usb-storage. There is some talk of better debuggability already, for example. The biggest problem with ub right now is that it's pissing Matt Dharm off by flooding him with retarded bug reports from users who: a) override default (which is set to ub off), b) ignore warnings in the help, c) cannot figure out what they just broke. If we had a way to make users like Jan to send reports to me instead, it would be great progress. Most are well-intentioned. The approach most seem to advocate is to create a better safety net for users by instilling palliatives such as making CONFIG_BLK_DEV_UB to depend on CONFIG_EXPERIMENTAL. Unfortunately, it's not likely to do much. If they override default settings, they are not likely to be deterred so simply. I'm considering printing some warnings into syslog, although it's terribly lame (remember the infamous "Data integrity not assured for USB storage"). This needs some thinking. Cheers, -- Pete