From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH]: Re: qla1280.c broken on SGI visws, PCI coherency problem Date: Tue, 13 Dec 2005 08:50:13 -0600 Message-ID: <1134485413.3356.2.camel@mulgrave> References: <4399D6EB.4080603@c-lab.de> <439A17BE.5000904@sgi.com> <439DE50B.90007@sgi.com> <1134424057.3713.18.camel@mulgrave> <439E0112.1030801@sgi.com> <439ECB2E.7070103@sgi.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from stat9.steeleye.com ([209.192.50.41]:11407 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S964980AbVLMOuk (ORCPT ); Tue, 13 Dec 2005 09:50:40 -0500 In-Reply-To: <439ECB2E.7070103@sgi.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Michael Reed Cc: pazke@donpac.ru, Michael Joosten , linux-scsi@vger.kernel.org On Tue, 2005-12-13 at 07:22 -0600, Michael Reed wrote: > I believe the biggest issue with VISWS is that it appears to need > mmiowb() and we likely don't know how to implement it. Hence, for > that platform, it would make sense to replace the mmiowb() with a > posting read. Well, there's an easy way to tell ... the reason for the mmiowb in the qla1280 driver is supposed to be an SMP race, according to the description, so if it fails on UP as well there's something else going on here ... I'm still suspicious because the mmiowb() in this driver replaced a posted write flush instruction, which altered the behaviour of the driver. The qla1280 is just rare enough that it might have taken this long to notice ... James