From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Neukum Subject: Re: [linux-usb-devel] Re: [PATCH] USB changes for 2.5.58 Date: Tue, 21 Jan 2003 01:50:55 +0100 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <200301210150.55286.oliver@neukum.name> References: <10426732153816@kroah.com> <200301210000.24705.oliver@neukum.name> <3E2C97D7.1070406@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: In-Reply-To: <3E2C97D7.1070406@pacbell.net> List-Id: linux-scsi@vger.kernel.org To: David Brownell Cc: Luben Tuikov , Matthew Dharm , Mike Anderson , Greg KH , linux-usb-devel@lists.sourceforge.net, Linux SCSI list Am Dienstag, 21. Januar 2003 01:44 schrieb David Brownell: > Oliver Neukum wrote: > >>So you were talking past what I said about notifying that highest level, > >>not disagreeing with it. > > > > I was trying to make the point that callbacks have no place in that > > process. > > If so, you didn't persuade me ... > > > It must go bottom to top and that's it. > > ... because those disconnect() callbacks are exactly how USB and PCI > deliver that notification to the "top" level, and you've already agreed > that SCSI needs to accomodate those models. So clearly they have at least > that much of a place. Disconnect is not really a callback. There's a distinct lack of a back movement here. khubd -> usbcore -> disconnect() in driver -> [layer on top] The proposed API in SCSI looks like: -> LLD -> midlayer -> top layer -> midlayer -> LLD with destroy_slave() and that's not OK. > > Refusing to take notice of a device removal is just not an option. > > This is exactly what the current SCSI idea of an API to do bus removal > > does. > > I perceive violent agreement that a change is needed in that area. > > But the next step there would seem to be a patch to the SCSI APIs, > unless I mis-understood what Matt was saying about the issue he ran > into when making usb-storage use the enumeration facilities in the > current SCSI mid/low layers. I have some horrible notions when I see what APIs grace the SCSI layer. Regards Oliver