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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57422C433EF for ; Thu, 28 Oct 2021 05:16:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A985610CA for ; Thu, 28 Oct 2021 05:16:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229689AbhJ1FTN (ORCPT ); Thu, 28 Oct 2021 01:19:13 -0400 Received: from smtp-relay-internal-1.canonical.com ([185.125.188.123]:49928 "EHLO smtp-relay-internal-1.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229651AbhJ1FTN (ORCPT ); Thu, 28 Oct 2021 01:19:13 -0400 Received: from mail-oi1-f200.google.com (mail-oi1-f200.google.com [209.85.167.200]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-1.canonical.com (Postfix) with ESMTPS id D7E2A3F194 for ; Thu, 28 Oct 2021 05:16:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1635398205; bh=w4w/09FZfuLDv9QiNpe09G8HG8kj8Rm/e85TyylOjKw=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=cq8VPEhi4dNnWSuwoD+76SyF0IyMDQq7pj1BWOAYsC1Z9+hi8ij78toj54FhEDlk6 SH3Vjq0gYLnFtW5pp/qy44IDNpUodLaSHHDBtah2jZ1DHOxPwpElpAeNuG3V5c7s77 9vhnVe7g5FHEbSSPTazUUuEXuHAAYk6HXrAakIyrLoejhyfjRpa3/a18f5hLJW53pY K4e65R3kIqJViAucrGPgjTQ9gMtW2DSQKl0OIP7CxFuuV6x/kN9Nj/cflYTPiZjFSD 8eMUtzn6hmgzPRrmwRWIaLoPVrqTQz9d0FfLAygOV6G0pIb5BS0gBHu5vUCUd6G3WK 64hH6/XZzd9zg== Received: by mail-oi1-f200.google.com with SMTP id v135-20020acaac8d000000b002995845aa8cso2530106oie.5 for ; Wed, 27 Oct 2021 22:16:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=w4w/09FZfuLDv9QiNpe09G8HG8kj8Rm/e85TyylOjKw=; b=xzMjUMHR0KL6rQ8jBJCrKxIodidrIe2Z02E1LrMAu/DhFa+yy1AnFesWo1DAy5EKPE VJJWpImeA8/TQmgbgowYmoe71kbemDljUsrS0C9ONgAasfgXcmJqbiRk5JT650dVKIB5 77/aoBEAohBCfwgdWK4GxsYdAW192Ns2e4mXodF3o3t+X74A3oRxnsYSGauE8yNtp4Mu bDTUcMcE8KVE9Wr9MCb2yfPf/z6Hhtj4+NP04kilRHaVuZlDMD8GZsjsVnPfCiF5lNHQ 77bUq2Pouhoev3zeTNHfm/K77Z2I4xC+vcdE6sSu5H0H1uozu6Q43yq6YYkPRggSZ2WE 2cwg== X-Gm-Message-State: AOAM533hj7Yzy/aG70HzKZdQ6yfiI0JtZ3Xdpw3WgwwhAsMLywYkoWPl vWgXJ2pcmeB9NmUeUQxgSSyqHxeO6SBaNWuH10TO+OMrwscUsaDyi9sWg1a0KsG8RneQU1ZAQfC LvVXoSoNMF/zCvwrM2WcEPuMubjcwb5/XhPzpvH9ixoLW2zvkVDLozw== X-Received: by 2002:a05:6830:1f55:: with SMTP id u21mr1681192oth.233.1635398204591; Wed, 27 Oct 2021 22:16:44 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzfyZgo2HvulEezaAHjWw86S1CWV6EW+zSNzZA3tyky5FFoj5l6UxkMTZtrDl5aLiXaNLUtCGTf+F91fY0Vkik= X-Received: by 2002:a05:6830:1f55:: with SMTP id u21mr1681178oth.233.1635398204356; Wed, 27 Oct 2021 22:16:44 -0700 (PDT) MIME-Version: 1.0 References: <20211026165348.GA146058@bhelgaas> In-Reply-To: <20211026165348.GA146058@bhelgaas> From: Kai-Heng Feng Date: Thu, 28 Oct 2021 13:16:31 +0800 Message-ID: Subject: Re: [PATCH v2 3/3] PCI/ASPM: Add LTR sysfs attributes To: Bjorn Helgaas Cc: Bjorn Helgaas , Heiner Kallweit , Anthony Wong , Linux PCI , LKML , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Vidya Sagar , Logan Gunthorpe Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Oct 27, 2021 at 12:53 AM Bjorn Helgaas wrote: > > On Tue, Oct 26, 2021 at 10:28:38AM +0800, Kai-Heng Feng wrote: > > > What if we fallback to the original approach and use the VMD driver > > to enable ASPM and LTR values? At least I think Intel should be > > able to provide correct values for their SoC. > > Can you post the patches for that? I'm not sure exactly what the > original approach was. Are these the same as the downstream support > you mention below? This is the previous attempt to enable VMD ASPM: https://lore.kernel.org/linux-pci/20200930082455.25613-1-kai.heng.feng@canonical.com/ It didn't enable LTR though. Right now the downstream kernel use PCI quirk to enable VMD ASPM and LTR: https://kernel.ubuntu.com/git/ubuntu/unstable.git/commit/?id=069ab00c2613d27cb7cdeb2a4c751de89dab81b4 https://kernel.ubuntu.com/git/ubuntu/unstable.git/commit/?id=1e4dec5fe846f8dd8954b173434670f8ae30b5ff The patches don't touch VMD driver to minimize merge conflict on VMD driver. I really hope we can put these changes to upstream VMD driver. Kai-Heng > > > So what other options do we have if we want to enable VMD ASPM while > > keeping CONFIG_PCIEASPM_DEFAULT=y? Right now we enabled the VMD > > ASPM/LTR bits in downstream kernel, but other distro users may want > > to have upstream support for this.