From mboxrd@z Thu Jan 1 00:00:00 1970 From: linas@austin.ibm.com (Linas Vepstas) Subject: Re: [PATCH 5/7] pci: Export the pci_restore_msi_state() function Date: Mon, 22 Oct 2007 19:13:07 -0500 Message-ID: <20071023001307.GF4280@austin.ibm.com> References: <1192829817.22064.559.camel@teletran1> <20071021.162131.43417026.davem@davemloft.net> <1193017764.10318.17.camel@concordia> <20071022181336.GC4280@austin.ibm.com> <1193088267.6745.108.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Michael Ellerman , netdev@vger.kernel.org, mcarlson@broadcom.com, linuxppc-dev list , mchan@broadcom.com, linux-pci@atrey.karlin.mff.cuni.cz, David Miller To: Benjamin Herrenschmidt Return-path: Received: from e31.co.us.ibm.com ([32.97.110.149]:59913 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753349AbXJWANK (ORCPT ); Mon, 22 Oct 2007 20:13:10 -0400 Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e31.co.us.ibm.com (8.13.8/8.13.8) with ESMTP id l9N0D9FH006599 for ; Mon, 22 Oct 2007 20:13:09 -0400 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v8.5) with ESMTP id l9N0D9e9069958 for ; Mon, 22 Oct 2007 18:13:09 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l9N0D8m7028405 for ; Mon, 22 Oct 2007 18:13:09 -0600 Content-Disposition: inline In-Reply-To: <1193088267.6745.108.camel@pasglop> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Oct 23, 2007 at 07:24:27AM +1000, Benjamin Herrenschmidt wrote: > > On Mon, 2007-10-22 at 13:13 -0500, Linas Vepstas wrote: > > On Mon, Oct 22, 2007 at 11:49:24AM +1000, Michael Ellerman wrote: > > > > > > On pseries there's a chance it will work for PCI error recovery, but if > > > so it's just lucky that firmware has left everything configured the same > > > way. > > > > ? The papr is quite clear that i is up to the OS to restore the msi > > state after an eeh error. > > Via direct config space access or via firmware change-msi calls ? Direct config space access. It says that the OS is supposed to read the MSI config (after its been set up), save it, and restore it, (via direct config space writes) if the device is ever reset. > I don't know why you keep talking about powerpc laptops here ... Well, there are Apple laptops, right? Aren't those the "powermac" platform? Now, I don't know if they support MSI, but if they do, I get the impression that they might not restore msi state correctly, after being put into hardware suspend. But perhaps I'm mistaken; I was simply grepping for various msi-related functions in various arch subdirectories, comparing x86 to other arches, and noticed that code that would restore msi state seems to be missing for most arches and most powerpc platforms. --linas