Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756085AbaLHX74 (ORCPT ); Mon, 8 Dec 2014 18:59:56 -0500 Received: from mail-ie0-f172.google.com ([209.85.223.172]:58018 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755744AbaLHX7z (ORCPT ); Mon, 8 Dec 2014 18:59:55 -0500 MIME-Version: 1.0 In-Reply-To: <1418079372.13358.9.camel@kernel.crashing.org> References: <1418075552-26495-1-git-send-email-yinghai@kernel.org> <1418079372.13358.9.camel@kernel.crashing.org> Date: Mon, 8 Dec 2014 15:59:54 -0800 X-Google-Sender-Auth: 0ntHFWQ16b7_zAxt7ZLMtrFsDMY Message-ID: Subject: Re: [PATCH] PCI: Clear bridge MEM_64 flag if one child does not support it From: Yinghai Lu To: Benjamin Herrenschmidt Cc: Bjorn Helgaas , Gavin Shan , =?UTF-8?Q?Marek_Kord=C3=ADk?= , Alexey Voronkov , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 8, 2014 at 2:56 PM, Benjamin Herrenschmidt wrote: > On Mon, 2014-12-08 at 13:52 -0800, Yinghai Lu wrote: >> 2. or scan the children resource other than ROM to clear bridge MEM_64 >> for mmio pref. >> >> The patch is using second way so will keep child mmio pref into bridge >> mmio pref range. > > That means that having a single ROM BAR that is 32-bit and prefetchable > will downgrade the entire window to 32-bit ? That's not going to work > either. the ROM BAR get skipped during the checking. + if (i != PCI_ROM_RESOURCE) + mem64_mask &= r->flags & IORESOURCE_MEM_64; + } > > I have GPUs with 16G BARs for example... suddenly they don't fit > anaymore because we downgraded the window to 32 bit because somewhere > there's a 32-bit pref resource ? > > That will break more than it fixes... Please check if this patch break your platform. I tried on my setup on x86. and it is still working on 64 bit resource allocation. Thanks Yinghai -- 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/