From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23DA4C43387 for ; Mon, 17 Dec 2018 14:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE0332146E for ; Mon, 17 Dec 2018 14:32:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545057170; bh=U3lJ6BneydpJBppucBLQPbsaaT46S5fpMxrOi3dnS5s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=WaU21VLDKQY+xKlUNl2m6IwkQfUSORE17Mi/Fcwfv35SAlMQwzhCf7BYFR3ynKd6b FYhLOQdQWUxTtD1aCE69f/CmsczU2MFr6vg5cl0pDMzsS75q/6dKMbuA5EYORr4U3u f7mwLF/C57mhFCO1oAV64jf+IKD3+9emqoy6z5Ak= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726812AbeLQOct (ORCPT ); Mon, 17 Dec 2018 09:32:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:55046 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726738AbeLQOct (ORCPT ); Mon, 17 Dec 2018 09:32:49 -0500 Received: from localhost (173-25-171-118.client.mchsi.com [173.25.171.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 496AB206A2; Mon, 17 Dec 2018 14:32:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545057168; bh=U3lJ6BneydpJBppucBLQPbsaaT46S5fpMxrOi3dnS5s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HepqszlaEMP64Nm+rnoLqwCkW2ORzS6Xlvc0jzE4+Q7WsoJ/TSzwUPvf6Z8lX9VCe 0VAlGGVDGi+1KOZMBATBDoGm/VvvdkwE6IMazCj3sohexQHJ6w0kcLtikJmJN/mTX5 XQg9bkFDLLNK/9QdtAq3ZZcTC5x9lURBuXw0vELg= Date: Mon, 17 Dec 2018 08:32:47 -0600 From: Bjorn Helgaas To: Jianjun Wang Cc: ryder.lee@mediatek.com, robh+dt@kernel.org, lorenzo.pieralisi@arm.com, matthias.bgg@gmail.com, linux-pci@vger.kernel.org, mark.rutland@arm.com, devicetree@vger.kernel.org, youlin.pei@mediatek.com, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, honghui.zhang@mediatek.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] PCI: mediatek: Add controller support for MT7629 Message-ID: <20181217143247.GK20725@google.com> References: <1544058553-10936-1-git-send-email-jianjun.wang@mediatek.com> <1544058553-10936-3-git-send-email-jianjun.wang@mediatek.com> <20181213145517.GB4701@google.com> <1545034779.8528.8.camel@mhfsdcap03> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1545034779.8528.8.camel@mhfsdcap03> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Dec 17, 2018 at 04:19:39PM +0800, Jianjun Wang wrote: > On Thu, 2018-12-13 at 08:55 -0600, Bjorn Helgaas wrote: > > On Thu, Dec 06, 2018 at 09:09:13AM +0800, Jianjun Wang wrote: > > > The read value of BAR0 is 0xffff_ffff, it's size will be calculated as 4GB > > > in arm64 but bogus alignment values at arm32, the pcie device and devices > > > behind this bridge will not be enabled. Fix it's BAR0 resource size to > > > guarantee the pcie devices will be enabled correctly. > > > > So this is a hardware erratum? Per spec, a memory BAR has bit 0 hardwired > > to 0, and an IO BAR has bit 1 hardwired to 0. > > Yes, it only works properly on 64bit platform. I don't understand. BARs are supposed to work the same regardless of whether it's a 32- or 64-bit platform. If this is a workaround for a hardware defect, please just say that explicitly. Bjorn