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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 7ECE8C43144 for ; Mon, 25 Jun 2018 12:52:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 447BA2598B for ; Mon, 25 Jun 2018 12:52:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 447BA2598B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755419AbeFYMwK (ORCPT ); Mon, 25 Jun 2018 08:52:10 -0400 Received: from mga18.intel.com ([134.134.136.126]:55908 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752109AbeFYMwI (ORCPT ); Mon, 25 Jun 2018 08:52:08 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jun 2018 05:52:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,270,1526367600"; d="scan'208";a="61023959" Received: from lahna.fi.intel.com (HELO lahna) ([10.237.72.157]) by fmsmga002.fm.intel.com with SMTP; 25 Jun 2018 05:52:05 -0700 Received: by lahna (sSMTP sendmail emulation); Mon, 25 Jun 2018 15:52:04 +0300 Date: Mon, 25 Jun 2018 15:52:04 +0300 From: Mika Westerberg To: Marc Zyngier Cc: Bjorn Helgaas , Lorenzo Pieralisi , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] PCI: shpchp: Fix probing logic inversion Message-ID: <20180625125204.GH2558@lahna.fi.intel.com> References: <20180621164715.28160-1-marc.zyngier@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180621164715.28160-1-marc.zyngier@arm.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 21, 2018 at 05:47:15PM +0100, Marc Zyngier wrote: > Until recently, shpc_probe() would bail out pretty early in the > absence of the SHPC capability. A logic change in the way the > driver now checks that capability makes it go and probe the > firmware anyway, with ugly consequences if the system is not > ACPI based (my arm64 ThunderX is DT driven, and explodes in > a spectacular way after getting a NULL root bridge from the > non-existent ACPI tables...). Could you share log from the failure? I would like to understand a bit better where it crashes and why. > Take this opportunity to move the call to shpchp_is_native() > back into shpc_probe(), making it clear that a non-ACPI system > is not expected to use this driver. It is fine to use SHPC in non-ACPI systems. However, in ACPI systems we should negotiate whether it is the OS or the firmware who handles it.