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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 32600C433E6 for ; Thu, 18 Mar 2021 17:34:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF20464F38 for ; Thu, 18 Mar 2021 17:34:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231925AbhCRReJ (ORCPT ); Thu, 18 Mar 2021 13:34:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232298AbhCRRdv (ORCPT ); Thu, 18 Mar 2021 13:33:51 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E081EC06174A for ; Thu, 18 Mar 2021 10:33:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=g9Fdqqrn2E7eJQyJmkmEHHk98x5Wf7OPugDcGnEMI4w=; b=s5sdxUYTWVZ1R/ElbpCE51YBVD xJLC79juLwHoEBVSPuVbMSFssi4gjN1ganZ8wzYpMLzuvCY3GknNX2Lf9GbTVMgKmUIPAiscJcI55 M2YELDgC9qdQwYt2P6mjMoe+3g0tyVgACmkXgc2ZIK4Uwhy+Z3/cEnZwx49HD9qiKrcVMruu7bfV4 Wt+aaAFyeQiZDfl6bKydpZ7wPQU7LkMopg+D5pk4hgqwq1roLXCp4Xw1D09uFAb+IutT7ajP6pqgC 5kM60NKmKf/4l9d5HtEk7uk2tA1Gm1AnbyFC227Ym9TEfxsCEvFnsg89StdJ4JBYknUBiJfcOKau8 4EIVXNlw==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lMwWT-003Hya-Ns; Thu, 18 Mar 2021 17:33:28 +0000 Date: Thu, 18 Mar 2021 17:33:25 +0000 From: Matthew Wilcox To: Bjorn Helgaas Cc: Martin Mares , Pali =?iso-8859-1?Q?Roh=E1r?= , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , linux-pci@vger.kernel.org, Bjorn Helgaas Subject: Re: [PATCH] lspci: Don't report PCIe link downgrades for downstream ports Message-ID: <20210318173325.GR3420@casper.infradead.org> References: <20210318170244.151240-1-helgaas@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210318170244.151240-1-helgaas@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Mar 18, 2021 at 12:02:44PM -0500, Bjorn Helgaas wrote: > Drop the "downgraded" reporting for Downstream Ports. If there is a device > below, we'll still complain at that end if it supports a faster/wider link > than is available. This makes sense, but I think we should still report if training has gone horribly wrong. Maybe something like this ... > +++ b/ls-caps.c > @@ -758,13 +758,16 @@ static char *link_speed(int speed) > } > } > > -static char *link_compare(int sta, int cap) > +static char *link_compare(int type, int sta, int cap) > { > + if ((type == PCI_EXP_TYPE_ROOT_PORT) || (type == PCI_EXP_TYPE_DOWNSTREAM) || > + (type == PCI_EXP_TYPE_PCIE_BRIDGE)) > + return ""; > if (sta < cap) > - return "downgraded"; > + return " (downgraded)"; > if (sta > cap) > - return "strange"; > - return "ok"; > + return " (strange)"; > + return " (ok)"; > } { if (sta > cap) return " (overdriven)"; if (sta == cap) return ""; if ((type == PCI_EXP_TYPE_ROOT_PORT) || ((type == PCI_EXP_TYPE_DOWNSTREAM) || ((type == PCI_EXP_TYPE_PCIE_BRIDGE)) return ""; return " (downgraded)"; } (i don't know if the PCIe spec has a better word than overdriven for this situation, but i don't like "strange". "invalid", maybe?) The reason i say we should report it on the downstream port is that we probably can't get to the config data on the upstream port/device, so this may be our best chance to find out what's wrong.