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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT autolearn=unavailable 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 884D6C10F00 for ; Thu, 28 Feb 2019 06:32:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 551C420842 for ; Thu, 28 Feb 2019 06:32:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730917AbfB1GcA (ORCPT ); Thu, 28 Feb 2019 01:32:00 -0500 Received: from bmailout3.hostsharing.net ([176.9.242.62]:57815 "EHLO bmailout3.hostsharing.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725862AbfB1GcA (ORCPT ); Thu, 28 Feb 2019 01:32:00 -0500 Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by bmailout3.hostsharing.net (Postfix) with ESMTPS id DC724100D940C; Thu, 28 Feb 2019 07:31:57 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 81416D6B92; Thu, 28 Feb 2019 07:31:57 +0100 (CET) Date: Thu, 28 Feb 2019 07:31:57 +0100 From: Lukas Wunner To: Alexandru Gagniuc Cc: bhelgaas@google.com, austin_bolen@dell.com, alex_gagniuc@dellteam.com, keith.busch@intel.com, Shyam_Iyer@Dell.com, okaya@kernel.org, "Rafael J. Wysocki" , Oza Pawandeep , Mika Westerberg , Benjamin Young , Frederick Lawler , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v3] PCI: portdrv: Report degraded links via link bandwidth notification Message-ID: <20190228063157.rl2lywgian2ij5m4@wunner.de> References: <20190227205840.26898-1-mr.nuke.me@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227205840.26898-1-mr.nuke.me@gmail.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 02:58:17PM -0600, Alexandru Gagniuc wrote: > A warning is generated when a PCIe device is probed with a degraded > link, but there was no similar mechanism to warn when the link becomes > degraded after probing. The Link Bandwidth Notification provides this > mechanism. > > Use the link bandwidth notification interrupt to detect bandwidth > changes, and rescan the bandwidth, looking for the weakest point. This > is the same logic used in probe(). > > Signed-off-by: Alexandru Gagniuc Reviewed-by: Lukas Wunner