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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53259C433EF for ; Fri, 15 Jul 2022 12:56:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233266AbiGOM4z convert rfc822-to-8bit (ORCPT ); Fri, 15 Jul 2022 08:56:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229928AbiGOM4x (ORCPT ); Fri, 15 Jul 2022 08:56:53 -0400 Received: from mail-yw1-f181.google.com (mail-yw1-f181.google.com [209.85.128.181]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3DC833A2F; Fri, 15 Jul 2022 05:56:51 -0700 (PDT) Received: by mail-yw1-f181.google.com with SMTP id 00721157ae682-31c89111f23so46433737b3.0; Fri, 15 Jul 2022 05:56:51 -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:content-transfer-encoding; bh=EJLO/iGBhSlgyO6zwD8vS0OkYuL2aYYUWRXoy69vUfs=; b=nQ0fgYN9AcQimJwztfaqCJy+V2hExa9pIDvceEs/JgSdM1M6Dct4nHP9hpzgaWaK1y amN4oHBb7HKLM/gQAwvp3MLbMIpHlsCUk/h79g20OeyqUMMyJQ+iFkr41/vVqHOWhmlm OhcL/E2o0NFeFRhgg8qd4JhRiMckFTJuFPEDQAqy/RIKqY9gxJgIB7ZuYc2Uakaus1fK 6Rv5aB/YjILLPifNAvGxLAMaV+wdTvTwyK3vUqI8QrNq+5cv38WRXDfhJKGL1/Cf7O8M quLB9qG6esvRW2TMSfVhAnrDWJV+mLJzkzrMKPcJjQCtj518yq0ccZqOJWMOmhQIKk4z Wpvw== X-Gm-Message-State: AJIora/TthsvJljKOCdm+JpGap7qbI5YlC8EnebwGaUU0ZQmjwBo637I GXYOOnvEJ0ezDkUI7dEJjDQaTRhnOdHeEMoygS9tuSNJxR4= X-Google-Smtp-Source: AGRyM1s8d2n+yzO7ii+LNQWP9PWRkh1qYkteVu/RvryNUyWW8W1BuGe9lR+fuJzingP0lT9Mk/oJvKwXsNldDbcWPp4= X-Received: by 2002:a0d:d952:0:b0:31d:789d:221c with SMTP id b79-20020a0dd952000000b0031d789d221cmr15341949ywe.515.1657889810968; Fri, 15 Jul 2022 05:56:50 -0700 (PDT) MIME-Version: 1.0 References: <20220713112612.6935-1-limanyi@uniontech.com> <20220713182852.GA841582@bhelgaas> <7305201c-eaf2-cb36-80fe-15174d3e33c7@uniontech.com> <20220715082945.GA10661@srcf.ucam.org> <20220715093236.GA12020@srcf.ucam.org> <62d14039.1c69fb81.86d3c.71c2SMTPIN_ADDED_BROKEN@mx.google.com> In-Reply-To: From: "Rafael J. Wysocki" Date: Fri, 15 Jul 2022 14:56:40 +0200 Message-ID: Subject: Re: [PATCH] PCI/ASPM: Should not report ASPM support to BIOS if FADT indicates ASPM is unsupported To: Manyi Li Cc: Matthew Garrett , Kai-Heng Feng , Bjorn Helgaas , Bjorn Helgaas , "Saheed O. Bolarinwa" , =?UTF-8?Q?Krzysztof_Wilczy=C5=84ski?= , Rajat Jain , Linux PCI , Linux Kernel Mailing List , Vidya Sagar , "Rafael J. Wysocki" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 15, 2022 at 2:32 PM Rafael J. Wysocki wrote: > > On Fri, Jul 15, 2022 at 12:23 PM Manyi Li wrote: > > > > > > > > On 2022/7/15 17:32, Matthew Garrett wrote: > > > On Fri, Jul 15, 2022 at 05:19:25PM +0800, Manyi Li wrote: > > >> > > >> > > >> On 2022/7/15 16:29, Matthew Garrett wrote: > > >>> On Fri, Jul 15, 2022 at 03:40:36PM +0800, Manyi Li wrote: > > >>> > > >>>> Please see the details of this issus: > > >>>> https://bugzilla.kernel.org/show_bug.cgi?id=216245 > > >>> > > >>> Hmm. The only case where changing aspm_support_enabled to false should > > >>> matter is in pcie_aspm_init_link_state(), where it looks like we'll > > >>> potentially rewrite some registers even if aspm_disabled is true. I > > >>> think in theory we shouldn't actually modify anything as a result, and > > >>> the lspcis from the bug don't show any ASPM values having changed, but I > > >>> don't trust Realtek hardware in the general case so maybe it gets upset > > >>> here? If the proposed patch is to just set aspm_support_enabled to false > > >>> when we see the FADT bit set then I think this is fine. > > >>> > > >> > > >> "aspm_support_enabled" alse be used in calculate_support(): > > >> if (pcie_aspm_support_enabled()) > > >> support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT; > > >> When set OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT, cause this AER > > >> issue. I want don't set OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT when > > >> we see the FADT bit set. > > > > > > Oh hm. Are you sure it's the OSC call that breaks it? I have some > > > > I don't sure. > > > > > recollection that I verified the behaviour of Windows here, but it's > > > been over 10 years since I touched this so I could well be wrong. I can > > > try to set up a test env to verify the behaviour of Windows when it > > > comes to _OSC if the FADT says ASPM is unsupported. > > > > > but, I did a test，this modification also solves the problem: > > > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > > index d57cf8454b93..b3ea8e886d7c 100644 > > --- a/drivers/acpi/pci_root.c > > +++ b/drivers/acpi/pci_root.c > > @@ -494,8 +494,8 @@ static u32 calculate_support(void) > > support |= OSC_PCI_HPX_TYPE_3_SUPPORT; > > if (pci_ext_cfg_avail()) > > support |= OSC_PCI_EXT_CONFIG_SUPPORT; > > - if (pcie_aspm_support_enabled()) > > - support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT; > > +// if (pcie_aspm_support_enabled()) > > +// support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT; > > if (pci_msi_enabled()) > > support |= OSC_PCI_MSI_SUPPORT; > > if (IS_ENABLED(CONFIG_PCIE_EDR)) > > > > This issue occur in the Notebook: ASUSTeK COMPUTER INC. X456UJ > > (ASUS-NotebookSKU) Notebook > > > > log "AER: Corrected error received: 0000:00:1c.5" is in the device: > > 00:1c.5 PCI bridge [0604]: Intel Corporation Sunrise Point-LP PCI > > Express Root Port #6 [8086:9d15] (rev f1) > > So it looks like the BIOS sets ACPI_FADT_NO_ASPM and then happily > grants control of ASPM via _OSC. That's somewhat contradictory. > > I would rather look at adjusting pcie_aspm_sanity_check() to this case > instead of wholesale changing the way _OSC is handled at the host > bridge level. Actually, if ACPI_FADT_NO_ASPM is set in the FADT, aspm_disabled should be set already when negotiate_os_control() runs? Can you please check if this is the case on the affected system? In that case, negotiate_os_control() doesn't need to set *no_aspm, because it only causes pcie_no_aspm() to be called, but it should have been called already.