Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030619AbVIBA6s (ORCPT ); Thu, 1 Sep 2005 20:58:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030620AbVIBA6r (ORCPT ); Thu, 1 Sep 2005 20:58:47 -0400 Received: from fmr18.intel.com ([134.134.136.17]:10222 "EHLO orsfmr003.jf.intel.com") by vger.kernel.org with ESMTP id S1030619AbVIBA6r (ORCPT ); Thu, 1 Sep 2005 20:58:47 -0400 Subject: RE: [RFC/PATCH]reconfigure MSI registers after resume From: Shaohua Li To: "Nguyen, Tom L" Cc: Greg KH , lkml , akpm In-Reply-To: References: Content-Type: text/plain Date: Fri, 02 Sep 2005 09:03:13 +0800 Message-Id: <1125622993.4010.6.camel@linux-hp.sh.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1531 Lines: 35 On Thu, 2005-09-01 at 23:20 +0800, Nguyen, Tom L wrote: > On Wednesday, August 31, 2005 2:44 PM Greg KH wrote: > >>On Thu, Aug 18, 2005 at 01:35:46PM +0800, Shaohua Li wrote: > >> Hi, > >> It appears pci_enable_msi doesn't reconfigure msi registers if it > >> successfully look up a msi for a device. It assumes the data and > address > >> registers unchanged after calling pci_disable_msi. But this isn't > always > >> true, such as in a suspend/resume circle. In my test system, the > >> registers unsurprised become zero after a S3 resume. This patch fixes > my > >> problem, please look at it. MSIX might have the same issue, but I > >> haven't taken a close look. > > > Tom, any comments on this? > > In the cases of suspend/resume, a device driver needs to restore its PCI > configuration space registers, which include the MSI/MSI-X capability > structures if a device uses MSI/MSI-X. I think reconfiguring MSI > data/address each time a driver calls pci_enable_msi may not be > necessary. Just when you called pci_disable_msi, reconfiguring MSI registers should be done. Is there any pain of reconfiguring MSI registers? I don't understand why should we have the assumption. If you disabled the ability, you must reconfigure it to me. This is the easy logic. Thanks, Shaohua - 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/