From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752377AbcHLOyR (ORCPT ); Fri, 12 Aug 2016 10:54:17 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39588 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbcHLOyN (ORCPT ); Fri, 12 Aug 2016 10:54:13 -0400 X-IBM-Helo: d01dlp02.pok.ibm.com X-IBM-MailFrom: jejb@linux.vnet.ibm.com Subject: Re: [PATCH] SAS: use sas_rphy instead of sas_end_device to obtain address. From: James Bottomley To: Hannes Reinecke , Johannes Thumshirn Cc: "Martin K . Petersen" , Linux SCSI Mailinglist , Linux Kernel Mailinglist , stable@vger.kernel.org, #@suse.de, v4.5+@suse.de Date: Fri, 12 Aug 2016 07:54:03 -0700 In-Reply-To: <75620aea-33df-9cf3-7eb2-ec209384eb4e@suse.de> References: <1470902352-96734-1-git-send-email-jthumshirn@suse.de> <1470928175.2334.9.camel@linux.vnet.ibm.com> <20160811164350.vakulxlr4xlsyrxn@c203.arch.suse.de> <1470938407.2334.36.camel@linux.vnet.ibm.com> <20160812100854.4cks5qxsommfwsjk@c203.arch.suse.de> <20160812131125.n7p47dcf7sinwg54@c203.arch.suse.de> <1471012475.2407.6.camel@linux.vnet.ibm.com> <75620aea-33df-9cf3-7eb2-ec209384eb4e@suse.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16081214-0056-0000-0000-00000109AD33 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00005583; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000181; SDB=6.00743694; UDB=6.00350229; IPR=6.00516231; BA=6.00004660; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00012328; XFM=3.00000011; UTC=2016-08-12 14:54:09 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16081214-0057-0000-0000-00000523FBF6 Message-Id: <1471013643.2407.14.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-08-12_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608120157 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2016-08-12 at 16:39 +0200, Hannes Reinecke wrote: > On 08/12/2016 04:34 PM, James Bottomley wrote: > > On Fri, 2016-08-12 at 15:11 +0200, Johannes Thumshirn wrote: > > > On Fri, Aug 12, 2016 at 12:08:54PM +0200, Johannes Thumshirn > > > wrote: > > > > Ok, we can't use the rphy because of wide-ports. We can't fix > > > > it to an end device either, as this makes some peoples systems > > > > unbootable. Now let's find a third option satisfying the needs > > > > of SAS wide-ports and my customers (and others running 4.5+ > > > > with a SAS enclosure). > > > > > > > > I'm digging... > > > > > > > > > To answer myself, Hannes suggested doing it like this: > > > > > > diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c > > > index 53ef1cb6..1d82053 100644 > > > --- a/drivers/scsi/ses.c > > > +++ b/drivers/scsi/ses.c > > > @@ -587,7 +587,7 @@ static void ses_match_to_enclosure(struct > > > enclosure_device *edev, > > > > > > ses_enclosure_data_process(edev, to_scsi_device(edev > > > ->edev.parent), 0); > > > > > > - if (is_sas_attached(sdev)) > > > + if (scsi_is_sas_rphy(&sdev->sdev_gendev)) > > > efd.addr = sas_get_address(sdev); > > > > > > if (efd.addr) { > > > > > > > > > The reasoning behind this is, we only read the address if we have > > > an actual sas_rphy. > > > > > > Would this be OK for you? > > > > Could you please debug the why? first before we start throwing > > patches around. is_sas_attached(sdev) returns true if the sdev is > > the child of a SAS controller. What is this thing you've found > > that has a sdev attached to a SAS controller but isn't and end > > device? > > > > if is_sas_attached() passes but scsi_is_sas_rphy() doesn't you've > > got a device that is the child of a SAS host which has an rphy but > > which isn't an expander or end device. That's pretty much the end > > of the list of things which can lie at the end of rphys since we > > lump the SATA possibilities in with end devices. > > > hpsa magic. > > The hpsa driver has some sdevs handled by the SAS transport class > (for the pass-through devices) and some sdevs (eg logical volumes) > which are not. As 'is_sas_attached' only checks if the _host_ has the > SAS transport class attached (which it will have), it will not work > as expected for devices which are not handled by the SAS transport > class (like the 'normal' hpsa logical volumes). And the logical > volumes don't even has a SAS address assigned to them, so in either > case the original check will draw a blank here. Thanks! I've found it in hpsa_add_device() for logical vs physical setups and, indeed, the way they call scsi_add_device will ensure that we don't attach the SAS transport class because the rphy isn't properly initialised so the last check (rphy->identify.device_type == SAS_END_DEVICE) won't pass .... in fact it's a bit of a mess. The change looks fine, since it's tighter than the original and, since this will be the last consumer of is_sas_attached(), you can remove that as well. James