Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754853AbbLDQRl (ORCPT ); Fri, 4 Dec 2015 11:17:41 -0500 Received: from mail.kernel.org ([198.145.29.136]:56339 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753460AbbLDQRj (ORCPT ); Fri, 4 Dec 2015 11:17:39 -0500 Date: Fri, 4 Dec 2015 10:17:35 -0600 From: Bjorn Helgaas To: Marc Zyngier Cc: Phil Edworthy , Thomas Gleixner , Jiang Liu , Bjorn Helgaas , "linux-kernel@vger.kernel.org" , Wolfram Sang , "linux-pci@vger.kernel.org" Subject: Re: [PATCH] PCI: MSI: Only use the generic MSI layer when domain is hierarchical Message-ID: <20151204161735.GA13427@localhost> References: <1448288826-19058-1-git-send-email-marc.zyngier@arm.com> <20151204002758.GA10479@localhost> <20151204081350.2113b7e6@why.wild-wind.fr.eu.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151204081350.2113b7e6@why.wild-wind.fr.eu.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2408 Lines: 57 On Fri, Dec 04, 2015 at 08:13:50AM +0000, Marc Zyngier wrote: > On Thu, 3 Dec 2015 18:27:59 -0600 > Bjorn Helgaas wrote: > > > On Mon, Nov 30, 2015 at 10:25:34AM +0000, Phil Edworthy wrote: > > > Cc'd linux-pci ml > > > > > > On 23 November 2015 14:27, Marc Zyngier wrote: > > > > > > Since d8a1cb757550 ("PCI/MSI: Let pci_msi_get_domain use struct > > > device::msi_domain"), we use the MSI domain associated to the PCI device. > > > > > > But finding a MSI domain doesn't mean that the domain is implemented > > > using the generic MSI domain API, and a number of MSI controllers > > > are still using the arch_setup_msi_irq/arch_teardown_msi_irqs. > > > > > > In order to avoid a firework on these systems, check that the domain > > > we just obtained is hierarchical. If not, don't use the generic MSI > > > stuff and stick with the old one. Not pretty, but reliable. > > > > > > Another insentive to rework those drivers and phase out this API. > > > > > > Reported-by: Phil Edworthy > > > Tested-by: Phil Edworthy > > > Signed-off-by: Marc Zyngier > > > > Thanks, I applied this with Thomas' ack to pci/msi for v4.5. > > > > It looks like d8a1cb757550 appeared in v4.3. Is this a fix for that > > commit? Does this need to be backported via a stable tag? > > Hi Bjorn, > > I think this really deserves to be queued as an immediate fix for 4.4 > rather than 4.5, as some systems in mainline are affected by this bug: > > http://www.spinics.net/lists/arm-kernel/msg465792.html > > It would also deserve a stable tag for 4.3. OK, I can do that. It would save me a lot of time to get a hint when this is the case. I couldn't tell if this issue happened on mainline or with some still out-of-tree patches. I'd also like to know what machines are affected. I did look at d8a1cb757550, and the connection between that and this patch is not completely obvious; would you regard this as a fix to d8a1cb757550? Should this patch be backported to every kernel that includes d8a1cb757550? Or is this more closely tied to some other change? Bjorn -- 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/