From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH v2][RFC] scsi_transport_fc: Implement I_T nexus reset Date: Tue, 11 Dec 2012 15:06:30 +0100 Message-ID: <50C73DE6.4090806@suse.de> References: <1355214219-17343-1-git-send-email-hare@suse.de> <1355230016.20256.6.camel@br8ggx07.de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:46527 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753667Ab2LKOGc (ORCPT ); Tue, 11 Dec 2012 09:06:32 -0500 In-Reply-To: <1355230016.20256.6.camel@br8ggx07.de.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Martin Peschke Cc: linux-scsi@vger.kernel.org On 12/11/2012 01:46 PM, Martin Peschke wrote: > Hello Hannes, > >> fc_eh_it_nexus_loss_handler() is invoked as the >> eh_target_reset_handler() callback and the >> eh_bus_reset_handler() is removed. > > lpfc_target_reset_handler(), which is replaced by your patch, used to > issue a TARGET_RESET task management function over FCP in the > eh_target_reset_handler() callback. What's wrong with that? > Nothing per se. Only that the TARGET_RESET TMF has been removed from SAM-3/FCP-3=20 onwards, so there might not be any functionality behind it. But drivers can supply the functionality via ->eh_it_nexus_loss=20 callback. I didn't want to touch the existing eh_target_reset_handler myself as I'm not familiar with the firmware specifics. That is being left as an exercise to the reader :-) The main point here is that we're emulating REMOVE I_T NEXUS by=20 setting the port state to BLOCKED and invoke dev_loss_tmo. This will prevent any further I/O to be send down. With the original handler the port state wasn't modified, which led to excessive recovery times when no RSCN was received. And yes, I had several bug reports now where the HBA did not receive=20 RSCNs, either due to a switch malfunction or due to an error injection. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: J. Hawn, J. Guild, F. Imend=C3=B6rffer, HRB 16746 (AG N=C3=BCrnberg= ) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html