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=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 699FCC433DF for ; Mon, 13 Jul 2020 08:27:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4966420758 for ; Mon, 13 Jul 2020 08:27:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594628872; bh=Mzu5M8J7qSSUdRCwII36kgtNKcgkXpCVKQg6uo3q2aM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=abAN4HzrRoncAXgOAGV6C0VlbZ9jQUbAoCoj79wT1V16lCZlwKyRUdDbeZGbQFY5O yE0lvTM1VwPZdVQkjz68qUHlbAqYoN4W6tfulI2M43oyIkUeLuOVLUCsuOiplnXgRH lTXUhTzzT2Iz4RJhKd0MhYhNvH6NEspLrFlqeJk8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729177AbgGMI1v (ORCPT ); Mon, 13 Jul 2020 04:27:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:59374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725818AbgGMI1u (ORCPT ); Mon, 13 Jul 2020 04:27:50 -0400 Received: from pali.im (pali.im [31.31.79.79]) (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 CA7FD2067D; Mon, 13 Jul 2020 08:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594628869; bh=Mzu5M8J7qSSUdRCwII36kgtNKcgkXpCVKQg6uo3q2aM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rBywLjk8q/9SCapOGSwOqN3Vg8NO4eBR99O6xSiKoblZ6EvtQULlpw0SYhMGfq1yX E385iR9JXzbY0Vl5jNNie7Nrv2DcIwUsZzy83qd8i/v9NzvIu/XMa1SdSTJdO13qWo aWbYjZSjZpteIpXWZwv7X29SmxWQNPC2bhh3WKIY= Received: by pali.im (Postfix) id E8996857; Mon, 13 Jul 2020 10:27:47 +0200 (CEST) Date: Mon, 13 Jul 2020 10:27:47 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Lorenzo Pieralisi Cc: Thomas Petazzoni , Andrew Murray , Bjorn Helgaas , Marek =?utf-8?B?QmVow7pu?= , Remi Pommarel , Tomasz Maciej Nowak , Xogium , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] PCI: aardvark: Don't touch PCIe registers if no card connected Message-ID: <20200713082747.e3q3ml3wpbszn4j7@pali> References: <20200528143141.29956-1-pali@kernel.org> <20200702083036.12230-1-pali@kernel.org> <20200709113509.GB19638@e121166-lin.cambridge.arm.com> <20200709122208.rmfeuu6zgbwh3fr5@pali> <20200709144701.GA21760@e121166-lin.cambridge.arm.com> <20200709150959.wq6zfkcy4m6hvvpl@pali> <20200710091800.GA3419@e121166-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200710091800.GA3419@e121166-lin.cambridge.arm.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 10 July 2020 10:18:00 Lorenzo Pieralisi wrote: > On Thu, Jul 09, 2020 at 05:09:59PM +0200, Pali Rohár wrote: > > > I understand that but the bridge bus resource can be trimmed to just > > > contain the root bus because that's the only one where there is a > > > chance you can enumerate a device. > > > > It is possible to register only root bridge without endpoint? > > It is possible to register the root bridge with a trimmed IORESOURCE_BUS > so that you don't enumerate anything other than the root port. Hello Lorenzo! I really do not know how to achieve it. From code it looks like that pci/probe.c scans child buses unconditionally. pci-aardvark.c calls pci_host_probe() which calls functions pci_scan_root_bus_bridge() which calls pci_scan_child_bus() which calls pci_scan_child_bus_extend() which calls pci_scan_bridge_extend() (bridge needs to be reconfigured) which then try to probe child bus via pci_scan_child_bus_extend() because bridge is not card bus. In function pci_scan_bridge_extend() I do not see a way how to skip probing for child buses which would avoid enumerating aardvark root bridge when PCIe device is not connected. dmesg output contains: advk-pcie d0070000.pcie: link never came up advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00 pci_bus 0000:00: root bus resource [bus 00-ff] pci_bus 0000:00: root bus resource [mem 0xe8000000-0xe8ffffff] pci_bus 0000:00: root bus resource [io 0x0000-0xffff] (bus address [0xe9000000-0xe900ffff]) pci_bus 0000:00: scanning bus pci 0000:00:00.0: [1b4b:0100] type 01 class 0x060400 pci 0000:00:00.0: reg 0x38: [mem 0x00000000-0x000007ff pref] pci_bus 0000:00: fixups for bus pci 0000:00:00.0: scanning [bus 00-00] behind bridge, pass 0 pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring pci 0000:00:00.0: scanning [bus 00-00] behind bridge, pass 1 pci_bus 0000:01: scanning bus advk-pcie d0070000.pcie: advk_pcie_valid_device 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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 89584C433E3 for ; Mon, 13 Jul 2020 08:29:12 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 56C602067D for ; Mon, 13 Jul 2020 08:29:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QW0tp6Sp"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="rBywLjk8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 56C602067D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HQB7sfIOaJN3B6EFKsEKbjJ5VePW07pfNaFxiKo6FkE=; b=QW0tp6SpHoKSloX2R4/m2bWOC Urnngq8MpXTCLTigtsghl80EaYMH14oH1/ytKyqhCHZzYZPUef82LNSTNPfPjGBSSKtAEA6qduo4Y CY19xMl+GkmvrKMebFGey/cnH645krlsfBV/ISf8XlZjFfEzsJASlkcLS29x97ZU0RIMsflK+wft3 UseUtqLh2gdFCOA9X22H7mkaoeexM8Tt1jONItJp015nsRw9LgeIOSCtBl3l9pyo46Pa46gfaOudd wG4XIf+st7Q9lQJc5I1LuOFfRbQ65xdq1YwldD7vFLAalNCWU7mfzi6JpZhewHo9wrcuvXL9pq26z JDnH8E5Og==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jutoY-0003sn-Be; Mon, 13 Jul 2020 08:27:54 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jutoV-0003r3-9y for linux-arm-kernel@lists.infradead.org; Mon, 13 Jul 2020 08:27:52 +0000 Received: from pali.im (pali.im [31.31.79.79]) (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 CA7FD2067D; Mon, 13 Jul 2020 08:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594628869; bh=Mzu5M8J7qSSUdRCwII36kgtNKcgkXpCVKQg6uo3q2aM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rBywLjk8q/9SCapOGSwOqN3Vg8NO4eBR99O6xSiKoblZ6EvtQULlpw0SYhMGfq1yX E385iR9JXzbY0Vl5jNNie7Nrv2DcIwUsZzy83qd8i/v9NzvIu/XMa1SdSTJdO13qWo aWbYjZSjZpteIpXWZwv7X29SmxWQNPC2bhh3WKIY= Received: by pali.im (Postfix) id E8996857; Mon, 13 Jul 2020 10:27:47 +0200 (CEST) Date: Mon, 13 Jul 2020 10:27:47 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Lorenzo Pieralisi Subject: Re: [PATCH v3] PCI: aardvark: Don't touch PCIe registers if no card connected Message-ID: <20200713082747.e3q3ml3wpbszn4j7@pali> References: <20200528143141.29956-1-pali@kernel.org> <20200702083036.12230-1-pali@kernel.org> <20200709113509.GB19638@e121166-lin.cambridge.arm.com> <20200709122208.rmfeuu6zgbwh3fr5@pali> <20200709144701.GA21760@e121166-lin.cambridge.arm.com> <20200709150959.wq6zfkcy4m6hvvpl@pali> <20200710091800.GA3419@e121166-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200710091800.GA3419@e121166-lin.cambridge.arm.com> User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200713_042751_441370_AA773C0F X-CRM114-Status: GOOD ( 16.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tomasz Maciej Nowak , linux-pci@vger.kernel.org, Xogium , linux-kernel@vger.kernel.org, Marek =?utf-8?B?QmVow7pu?= , Remi Pommarel , Thomas Petazzoni , Bjorn Helgaas , linux-arm-kernel@lists.infradead.org, Andrew Murray Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gRnJpZGF5IDEwIEp1bHkgMjAyMCAxMDoxODowMCBMb3JlbnpvIFBpZXJhbGlzaSB3cm90ZToK PiBPbiBUaHUsIEp1bCAwOSwgMjAyMCBhdCAwNTowOTo1OVBNICswMjAwLCBQYWxpIFJvaMOhciB3 cm90ZToKPiA+ID4gSSB1bmRlcnN0YW5kIHRoYXQgYnV0IHRoZSBicmlkZ2UgYnVzIHJlc291cmNl IGNhbiBiZSB0cmltbWVkIHRvIGp1c3QKPiA+ID4gY29udGFpbiB0aGUgcm9vdCBidXMgYmVjYXVz ZSB0aGF0J3MgdGhlIG9ubHkgb25lIHdoZXJlIHRoZXJlIGlzIGEKPiA+ID4gY2hhbmNlIHlvdSBj YW4gZW51bWVyYXRlIGEgZGV2aWNlLgo+ID4gCj4gPiBJdCBpcyBwb3NzaWJsZSB0byByZWdpc3Rl ciBvbmx5IHJvb3QgYnJpZGdlIHdpdGhvdXQgZW5kcG9pbnQ/Cj4gCj4gSXQgaXMgcG9zc2libGUg dG8gcmVnaXN0ZXIgdGhlIHJvb3QgYnJpZGdlIHdpdGggYSB0cmltbWVkIElPUkVTT1VSQ0VfQlVT Cj4gc28gdGhhdCB5b3UgZG9uJ3QgZW51bWVyYXRlIGFueXRoaW5nIG90aGVyIHRoYW4gdGhlIHJv b3QgcG9ydC4KCkhlbGxvIExvcmVuem8hIEkgcmVhbGx5IGRvIG5vdCBrbm93IGhvdyB0byBhY2hp ZXZlIGl0LiBGcm9tIGNvZGUgaXQKbG9va3MgbGlrZSB0aGF0IHBjaS9wcm9iZS5jIHNjYW5zIGNo aWxkIGJ1c2VzIHVuY29uZGl0aW9uYWxseS4KCnBjaS1hYXJkdmFyay5jIGNhbGxzIHBjaV9ob3N0 X3Byb2JlKCkgd2hpY2ggY2FsbHMgZnVuY3Rpb25zCnBjaV9zY2FuX3Jvb3RfYnVzX2JyaWRnZSgp IHdoaWNoIGNhbGxzIHBjaV9zY2FuX2NoaWxkX2J1cygpIHdoaWNoIGNhbGxzCnBjaV9zY2FuX2No aWxkX2J1c19leHRlbmQoKSB3aGljaCBjYWxscyBwY2lfc2Nhbl9icmlkZ2VfZXh0ZW5kKCkgKGJy aWRnZQpuZWVkcyB0byBiZSByZWNvbmZpZ3VyZWQpIHdoaWNoIHRoZW4gdHJ5IHRvIHByb2JlIGNo aWxkIGJ1cyB2aWEKcGNpX3NjYW5fY2hpbGRfYnVzX2V4dGVuZCgpIGJlY2F1c2UgYnJpZGdlIGlz IG5vdCBjYXJkIGJ1cy4KCkluIGZ1bmN0aW9uIHBjaV9zY2FuX2JyaWRnZV9leHRlbmQoKSBJIGRv IG5vdCBzZWUgYSB3YXkgaG93IHRvIHNraXAKcHJvYmluZyBmb3IgY2hpbGQgYnVzZXMgd2hpY2gg d291bGQgYXZvaWQgZW51bWVyYXRpbmcgYWFyZHZhcmsgcm9vdApicmlkZ2Ugd2hlbiBQQ0llIGRl dmljZSBpcyBub3QgY29ubmVjdGVkLgoKZG1lc2cgb3V0cHV0IGNvbnRhaW5zOgoKICBhZHZrLXBj aWUgZDAwNzAwMDAucGNpZTogbGluayBuZXZlciBjYW1lIHVwCiAgYWR2ay1wY2llIGQwMDcwMDAw LnBjaWU6IFBDSSBob3N0IGJyaWRnZSB0byBidXMgMDAwMDowMAogIHBjaV9idXMgMDAwMDowMDog cm9vdCBidXMgcmVzb3VyY2UgW2J1cyAwMC1mZl0KICBwY2lfYnVzIDAwMDA6MDA6IHJvb3QgYnVz IHJlc291cmNlIFttZW0gMHhlODAwMDAwMC0weGU4ZmZmZmZmXQogIHBjaV9idXMgMDAwMDowMDog cm9vdCBidXMgcmVzb3VyY2UgW2lvICAweDAwMDAtMHhmZmZmXSAoYnVzIGFkZHJlc3MgWzB4ZTkw MDAwMDAtMHhlOTAwZmZmZl0pCiAgcGNpX2J1cyAwMDAwOjAwOiBzY2FubmluZyBidXMKICBwY2kg MDAwMDowMDowMC4wOiBbMWI0YjowMTAwXSB0eXBlIDAxIGNsYXNzIDB4MDYwNDAwCiAgcGNpIDAw MDA6MDA6MDAuMDogcmVnIDB4Mzg6IFttZW0gMHgwMDAwMDAwMC0weDAwMDAwN2ZmIHByZWZdCiAg cGNpX2J1cyAwMDAwOjAwOiBmaXh1cHMgZm9yIGJ1cwogIHBjaSAwMDAwOjAwOjAwLjA6IHNjYW5u aW5nIFtidXMgMDAtMDBdIGJlaGluZCBicmlkZ2UsIHBhc3MgMAogIHBjaSAwMDAwOjAwOjAwLjA6 IGJyaWRnZSBjb25maWd1cmF0aW9uIGludmFsaWQgKFtidXMgMDAtMDBdKSwgcmVjb25maWd1cmlu ZwogIHBjaSAwMDAwOjAwOjAwLjA6IHNjYW5uaW5nIFtidXMgMDAtMDBdIGJlaGluZCBicmlkZ2Us IHBhc3MgMQogIHBjaV9idXMgMDAwMDowMTogc2Nhbm5pbmcgYnVzCiAgYWR2ay1wY2llIGQwMDcw MDAwLnBjaWU6IGFkdmtfcGNpZV92YWxpZF9kZXZpY2UKCl9fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0Cmxp bnV4LWFybS1rZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFk Lm9yZy9tYWlsbWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK