From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Milburn Subject: Re: [PATCH 1/1] ahci: Do not receive interrupts sent by dummy ports Date: Thu, 17 Apr 2014 12:50:50 -0500 Message-ID: <5350147A.10403@redhat.com> References: <20140417170641.GR15326@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19475 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751001AbaDQRvM (ORCPT ); Thu, 17 Apr 2014 13:51:12 -0400 In-Reply-To: <20140417170641.GR15326@htj.dyndns.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: Alexander Gordeev , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org On 04/17/2014 12:06 PM, Tejun Heo wrote: > On Thu, Apr 17, 2014 at 06:06:15PM +0200, Alexander Gordeev wrote: >> In multiple MSI mode all AHCI ports (including dummy) get >> assigned separate MSI vectors and (as result of execution >> pci_enable_msi_exact() function) separate IRQ numbers, >> (mapped to the MSI vectors). >> >> Therefore, although interrupts from dummy ports are not >> desired they are still enabled. We do not request IRQs >> for dummy ports, but that only means we do not assign >> AHCI-specific ISRs to corresponding IRQ numbers. >> >> As result, dummy port interrupts still could come and >> traverse all the way from the PCI device to the kernel, >> causing unnecessary overhead. >> >> This update disables IRQs for dummy ports and prevents >> the described issue. >> >> Signed-off-by: Alexander Gordeev >> Cc: Tejun Heo >> Cc: David Milburn >> Cc: linux-ide@vger.kernel.org > > David, can you please test the patch? > Hi, I have re-tested successfully, this patch prevents the crash when using kdump, and I boot tested a system that boots off ahci and has dummy ports present, no problems seen. Thanks, David