From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luben Tuikov Subject: Re: [RFC]: 64 bit LUN/Tags, dummy device in host_queue, host_lock <-> LLDDreentrancy Date: Tue, 27 Aug 2002 17:04:00 -0400 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <3D6BE940.98A85C26@splentec.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from splentec.com (canoe.splentec.com [209.47.35.250]) by pepsi.splentec.com (8.11.6/8.11.0) with ESMTP id g7RL3vH14523 for ; Tue, 27 Aug 2002 17:03:57 -0400 List-Id: linux-scsi@vger.kernel.org To: linux-scsi Aron Zeh wrote: > > That's exactly where my question comes in. How do we see that an > asynchronous > reconfiguration on unit level has taken place? Unit Attentions are only > reported > in piggy-back fashion on top of a command per the standard you quoted (if I > did not misread it). > If a unit was just added to the configuration (and holds "unit was just > powered on" attention) > then I cannot see how Linux could find out. Yes, we have a similar conundrum. Well, a notification is needed just because the transport has to know in order to process properly any resevations/etc. But all this is transport specific and UA is what SAM-3 specifies as per Target/Initiator architecture (client/server). (SAM-3, 4.6(.1)) This model is properly preserved in Linux by the Scsi_Host_Template. > So you're ruling out the use of transport specific hotplug notifications > like RSCN on FC? Not really ``ruling out'', but you can notify of such an event by other means. > I currently cannot quite see how this would work. Isn't there always the > need to interpret reconfigurations of the hardware used to transport SAM-3 > data on a lower level? Or has SAM-3 some capabilites for doing just that > that I have missed? SAM-3 doesn't provide for ``hotplugging''. It's the whole server/client architecture. Since a human/robot is doing the hotplugging, such events can be notified of by other means. -- Luben