Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756877AbYGLDre (ORCPT ); Fri, 11 Jul 2008 23:47:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751482AbYGLDrZ (ORCPT ); Fri, 11 Jul 2008 23:47:25 -0400 Received: from gate.crashing.org ([63.228.1.57]:46620 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753210AbYGLDrY (ORCPT ); Fri, 11 Jul 2008 23:47:24 -0400 Subject: Re: [PATCH] PCI: Add support for multiple MSI From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Hidetoshi Seto Cc: Matthew Wilcox , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, grundler@parisc-linux.org, mingo@elte.hu, tglx@linutronix.de, jgarzik@pobox.com, linux-ide@vger.kernel.org, suresh.b.siddha@intel.com, jbarnes@virtuousgeek.org, rdunlap@xenotime.net, mtk.manpages@gmail.com, Matthew Wilcox In-Reply-To: <487719AC.9070609@jp.fujitsu.com> References: <20080711005719.GO14894@parisc-linux.org> <1215738002-4961-2-git-send-email-matthew@wil.cx> <487719AC.9070609@jp.fujitsu.com> Content-Type: text/plain Date: Sat, 12 Jul 2008 13:45:42 +1000 Message-Id: <1215834342.7549.151.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1071 Lines: 24 On Fri, 2008-07-11 at 17:28 +0900, Hidetoshi Seto wrote: > Hi, > > First of all, it seems that mask/unmask of MSI has problems. > - Per-vector masking is optional for MSI, so I think that allocating > multiple messages for a function without masking capability would be > not good idea, since all vector in the block will be masked/unmasked > at once without any agreement. > - Even if the function supports per-vector masking, current > mask/unmask_msi_irq() functions assume that MSI uses only one vector, > therefore they only set/unset the first bit of the maskbits which > for the first vector of the block. The bits for other vectors are > initialized as 'masked' but no one unmask them. I tend to think we should just do soft-masking anyway for MSI... better than whacking config space. Ben -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/