From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: qla_wxyz pci_set_mwi question Date: Fri, 13 Apr 2007 12:34:22 +1000 Message-ID: <1176431662.5764.56.camel@localhost.localdomain> References: <20070411221507.69c97257.randy.dunlap@oracle.com> <20070412172038.GG10124@andrew-vasquezs-computer.local> <20070412185347.GL26692@parisc-linux.org> <20070412193713.GB14510@andrew-vasquezs-computer.local> <20070412200438.GM26692@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from gate.crashing.org ([63.228.1.57]:42822 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753071AbXDMCep (ORCPT ); Thu, 12 Apr 2007 22:34:45 -0400 In-Reply-To: <20070412200438.GM26692@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: Andrew Vasquez , Randy Dunlap , scsi , gregkh , David Somayajulu , linuxppc-dev@ozlabs.org, linux-driver@qlogic.com, PCI On Thu, 2007-04-12 at 14:04 -0600, Matthew Wilcox wrote: > On Thu, Apr 12, 2007 at 12:37:13PM -0700, Andrew Vasquez wrote: > > On Thu, 12 Apr 2007, Matthew Wilcox wrote: > > > Why should it fail? If there's a platform which can't support a > > > cacheline size that the qla2xyz card can handle, it should be able to > > > happily fall back to doing plain writes instead of MWIs. IMO, it should > > > just call pci_set_mwi() and ignore the result. > > > > I believe there were some erratas on some ISP2xxx chips where MWI > > needed to be set for proper operation. I'll go back, verify and > > update the patch accordingly. > > Hmm. The thing is that pci_set_mwi() returns success on machines where > MWI is disabled (currently only PPC64). Perhaps it needs to fail > instead. MWI isn't diabled on ppc64... or did I miss something ? Ben.