From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:53836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727438AbfGCBIF (ORCPT ); Tue, 2 Jul 2019 21:08:05 -0400 Date: Tue, 2 Jul 2019 15:19:14 -0500 From: Bjorn Helgaas Subject: Re: Archs using generic PCI controller drivers vs. resource policy Message-ID: <20190702201914.GD128603@google.com> References: <5f3dcc3a8dafad188e3adb8ee9cf347bebdee7f6.camel@kernel.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f3dcc3a8dafad188e3adb8ee9cf347bebdee7f6.camel@kernel.crashing.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt Cc: linux-pci@vger.kernel.org, linux-arch@vger.kernel.org On Sun, Jun 23, 2019 at 10:30:42AM +1000, Benjamin Herrenschmidt wrote: > Hi ! > > As part of my cleanup and consolidation of the PCI resource assignment > policies, I need to clarify something. > > At the moment, unless PCI_PROBE_ONLY is set, a number of > platforms/archs expect Linux to reassign everything rather than honor > what has setup, then (re)assign what's left or broken. I don't think "reassign everything" is any different from "honor what has been setup and (re)assign what's left or broken". "Reassign everything" is clearly allowed to produce the exact same result as "honor what has been setup and (re)assign what's left or broken". I claim any difference between the two is actually a fragile dependency on the Linux assignment algorithm that is likely to break as that algorithm changes. Or am I missing something? Bjorn