From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 06/21] lpfc: Fix host reset escalation killing all IOs. Date: Fri, 10 Apr 2015 08:10:38 +0200 Message-ID: <5527695E.4050109@suse.de> References: <1428095489.6933.34.camel@myfc17> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:59223 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751924AbbDJGKk (ORCPT ); Fri, 10 Apr 2015 02:10:40 -0400 In-Reply-To: <1428095489.6933.34.camel@myfc17> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: james.smart@emulex.com, linux-scsi@vger.kernel.org On 04/03/2015 11:11 PM, James Smart wrote: > Fix host reset escalation killing all IOs. >=20 > SLI-3 adapters will use a new host template. The template differs > from SLI-4 adapters in that it does not have an eh_host_reset_handler= =2E >=20 > Lpfc has traditionally never had a host_reset. The host reset > handler was added when we ran into a stuck hardware condition on a > SLI-4 adapter. The host_reset will reset and reinit the pci function, > clearing the hardware condition. >=20 > Unfortunately, the host reset handler uses attach/detach code paths, > which makes scsi_add_host() and scsi_remove_host() calls. Meaning, a > host_reset will completely remove the scsi_host from the system. As a > new call to scsi_add_host() is made, the shost# changes, which result= s > in completely new scsi_devices and device names. All the older scsi > devices on the old shost# are now orphaned and unrecoverable. >=20 > We realize we need to re-implement the host_reset_handler so the scsi= _host > stays registered across the host_reset, but that will be a rather > lengthy effort. In the short term, we had an immediate need to restor= e > the SLI-3 devices to their working behavior, with the easiest path be= ing > to remove their host_reset handler. >=20 > Signed-off-by: Dick Kennedy > Signed-off-by: James Smart > --- Of course, this will disable the eh_deadline mechanism, which relies on the host_reset to be present. Of which you are perfectly aware :-) So, grudgingly: Reviewed-by: Hannes Reinecke 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