From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: Re: [PATCH] USB changes for 2.5.58 Date: Mon, 20 Jan 2003 13:24:08 -0800 Sender: linux-usb-devel-admin@lists.sourceforge.net Message-ID: <3E2C68F8.7080405@pacbell.net> References: <10426732153816@kroah.com> <3E2C3380.3070700@splentec.com> <3E2C5750.2040301@pacbell.net> <200301202148.23210.oliver@neukum.name> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7BIT Return-path: Errors-To: linux-usb-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Oliver Neukum Cc: Luben Tuikov , Matthew Dharm , Mike Anderson , Greg KH , linux-usb-devel@lists.sourceforge.net, Linux SCSI list List-Id: linux-scsi@vger.kernel.org Oliver Neukum wrote: > That model cannot be applied to SCSI as it is much more diverse > in the number of bus types it supports. > USB can do it, because it knows about hubs. SCSI cannot, > as there are no hubs in SCSI. Hubs are irrelevant here, the key functionality is noticing hardware addition/disconnect. Parts of it can be done in bus adapter code, parts of it can't. SCSI probes LUNS in much the same way khubd probes hub ports, and as I recall most of that logic isn't any more specific to the adapter than virtual root hub code is for USB. >>Those disconnect() callbacks have a few key responsibilities, very >>much including shutting down the entire higher level I/O queue to >>that device. I think you're saying that SCSI drivers don't have >>such a responsibility (unlike USB or PCI) ... if so, that would >>seem to be worth changing. > > > If the scsi layer cannot on its own detect that a device or a bus is gone, > there'll be no sense in having a callback. It's just a complication. Erm ... which of the three SCSI layers are you talking about? I was talking about the highest level, which is precisely the layer I think has been identified as already needing to know when to shut down the I/O queues (sd_mod and friends). - Dave ------------------------------------------------------- This SF.NET email is sponsored by: FREE SSL Guide from Thawte are you planning your Web Server Security? Click here to get a FREE Thawte SSL guide and find the answers to all your SSL security issues. http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0026en _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel