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=-10.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 D464BC433E4 for ; Mon, 27 Jul 2020 21:17:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACAAC20792 for ; Mon, 27 Jul 2020 21:17:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kXKRCCzD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgG0VRs (ORCPT ); Mon, 27 Jul 2020 17:17:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726110AbgG0VRr (ORCPT ); Mon, 27 Jul 2020 17:17:47 -0400 Received: from mail-qv1-xf41.google.com (mail-qv1-xf41.google.com [IPv6:2607:f8b0:4864:20::f41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2DC8C061794 for ; Mon, 27 Jul 2020 14:17:47 -0700 (PDT) Received: by mail-qv1-xf41.google.com with SMTP id a19so2185792qvy.3 for ; Mon, 27 Jul 2020 14:17:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=pKArutiGe7jj4mj6RmCQjYpYxaXVDrpcmCYcwBdJLbQ=; b=kXKRCCzDYN2ooH/QE7ZbQcaIP8GjAoT1lbf6QD8ORLiPFgFQ2CWBwpzDB8s61IgHga 5FruRgXDSqUD5iVPqFss2zJqCydnon9WoOK0E2T0DFbDZjQFN1MNUe3UpJS8x6aJce5Q n4MlJaatzI4B0EsOPdjhczqR6uBo7KbZbZ6xO2qa4m5yQss4eEjEwEXjDlL/uI7l82m6 jgNuN1J9a9UhHO2wk68E09kIZZhCDmzCs/WgY0wpVykd9CFdUTa1gwLSUbI/9xYefOfM 7Wx4QwxJcLEOMmxD7Ss3/2oxEZThPd6mueSlZUbqkWgKc8yCOTMUcIN0M5LW/neAY34s tJeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=pKArutiGe7jj4mj6RmCQjYpYxaXVDrpcmCYcwBdJLbQ=; b=d315UAZ6Ux+pXlE9Z83JQGd3jjpCYPWQfHL7cbI2tIWCPPDS5NUVpnF1zdtuIEhvN8 3E0s3RVRrKsc09KgCuEWeR80m2ccvL0eE7S+N7HDBtFdU1gSQIdbmLFXf3VUKFEOpbhn /PfAR8AXNf6UjXkS5o5LRno+1RxgHzUFXVCIhVZcpyr8mZYKXmRQ8aPGbUi14oym45nC Bw2cQVxuZcjbDDf88o4HWDblW/+jLYNzPwRIPg2JSeyWSZZs2MmdM8k19c0E+i77gVlj Nt7V9Sza6U/AwW18dwAOdhZeXElb9NrQo63DbPf1Rm82DucPHExU/NpKVnQCDQkOcKg/ 4V+g== X-Gm-Message-State: AOAM533Xmjgf6Xug8nq8ly7EaENUs9MgXSEoBpk24ozfL+sP9NFFca06 K5fGDjDeBABH3XClNDqMctWCbSYInLRrgRHX5rxQS9R6 X-Google-Smtp-Source: ABdhPJxmAXUFGeRNjGSy/yhZNOWmqLbetWTkoPc8BBZlr663M2RTHZ5cGB8w8LBEjJioVHjkpELhe/ajX+SUbvKSgvE= X-Received: by 2002:a0c:b665:: with SMTP id q37mr21220293qvf.75.1595884666710; Mon, 27 Jul 2020 14:17:46 -0700 (PDT) MIME-Version: 1.0 References: <20200726220653.635852-1-ian.kumlien@gmail.com> <20200726220653.635852-2-ian.kumlien@gmail.com> In-Reply-To: <20200726220653.635852-2-ian.kumlien@gmail.com> From: Ian Kumlien Date: Mon, 27 Jul 2020 23:17:35 +0200 Message-ID: Subject: Re: [PATCH] Use maximum latency when determining L1 ASPM To: linux-pci@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Sorry, the changelog is broken -- Will resend... That'll teach me for thinking after working out... =) On Mon, Jul 27, 2020 at 12:07 AM Ian Kumlien wrote: > > The current solution verifies per "hop" but doesn't > check the maximum latency, instead it checks the > current "hops" max latency for upstream and downstrea, > > This would work if all "hops" have the same latency, but: > > root -> a -> b -> c -> endpoint > > If c or b has the higest latency, it might not register > > Fix this by maintaining a maximum value for comparison > > Signed-off-by: Ian Kumlien > --- > drivers/pci/pcie/aspm.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index b17e5ffd31b1..bd53fba7f382 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -434,7 +434,7 @@ static void pcie_get_aspm_reg(struct pci_dev *pdev, > > static void pcie_aspm_check_latency(struct pci_dev *endpoint) > { > - u32 latency, l1_switch_latency = 0; > + u32 latency, l1_max_latency = 0, l1_switch_latency = 0; > struct aspm_latency *acceptable; > struct pcie_link_state *link; > > @@ -470,8 +470,9 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint) > * substate latencies (and hence do not do any check). > */ > latency = max_t(u32, link->latency_up.l1, link->latency_dw.l1); > + l1_max_latency = max_t(u32, latency, l1_max_latency); > if ((link->aspm_capable & ASPM_STATE_L1) && > - (latency + l1_switch_latency > acceptable->l1)) > + (l1_max_latency + l1_switch_latency > acceptable->l1)) > link->aspm_capable &= ~ASPM_STATE_L1; > l1_switch_latency += 1000; > > -- > 2.27.0 >