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 249FDC25B08 for ; Tue, 23 Aug 2022 03:48:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239596AbiHWDsK (ORCPT ); Mon, 22 Aug 2022 23:48:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239380AbiHWDsG (ORCPT ); Mon, 22 Aug 2022 23:48:06 -0400 Received: from smtp-relay-internal-1.canonical.com (smtp-relay-internal-1.canonical.com [185.125.188.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AEB15E316 for ; Mon, 22 Aug 2022 20:48:05 -0700 (PDT) Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (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 9271B40AFC for ; Tue, 23 Aug 2022 03:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1661226483; bh=mtCEp4uiimBkFVG2jUbW2sWT9JVevWVVixkZgdiNhJM=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=dw4hpkhE2BJCkYhMn+LbB7DHX8L0z13awZPmTm54TBCwjAoC7v+PZV+eTLkgI5CXE TcxbJpfna3jfQZ/LTIKxj66qbdj1zNpIxJuHH/Vp5yjRC0uAsDfOQQ+RgzYSC3zAbB AqZXpo1/UqF+WqlxrbyeiFdmHiaSjLmQ8dGP90243c8dq+myQWNoTSo432MzhbOdNt NDHEM2NHLTEVWP4xnN8hMwbH+0yX2+9RMsMyjco6Jt0x8W0hPal6wyK2F2tPBDCjci nwBRdJrWGR/r0yLxDafePJxWs1uDOAn7E8hjVCT6B4YdQ2/xMTKIMhnDeF6T6dADf4 ndE7nDox5kkeQ== Received: by mail-oi1-f197.google.com with SMTP id u10-20020a54438a000000b003451c5e52b2so4182061oiv.10 for ; Mon, 22 Aug 2022 20:48:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc; bh=mtCEp4uiimBkFVG2jUbW2sWT9JVevWVVixkZgdiNhJM=; b=dp3ucHfKTbS+onKDHpKnubi1ksXAuMVPPOZjSQD8YiWK1mT7Q3OCRYk3yk+N8GYEue fVCpWzKj+8v2JsY1OAEqlApAat2fgcBAPQTWtKG1VIM5y1SiTDjdhk6blMrj5CHxI1NK rlB2Q0nRh36ornFyfA6m6+wm+eilXH8wYBNemtq+Anj1lxliudbxggm7IDoCabXtAEnd cCjJBnHPk3fsYCV59sI3H7Ky7ug9T9xMktC8CQEQnNBcr6IxiZpj+OrDr3+8mDXj52bW kRh6DOkfW5Hop4mf0nzDPePNEEL3dTX79YlhQA0U8/gsqKLNn9YIOSZerjPn3BMDYoUL EjQQ== X-Gm-Message-State: ACgBeo1uzu0IGTJApmBCsBdquH8aLDGEx16bQebTg3Lc2nU/8f/s4i8y vBsivDaW10t1EThCTEdjlpw8dFan0ajWJLrxpVV9JW/06sVXgs4K3d8PD2bqO84ZR1q1KL7ckA6 Zm9aOrJfCAtWaENxzU6U49GTTwQt8vAVf8RxBjjKJj4jXBALtOGUgJp8ATQ== X-Received: by 2002:a05:6870:8901:b0:11d:416d:2ccb with SMTP id i1-20020a056870890100b0011d416d2ccbmr583919oao.176.1661226482273; Mon, 22 Aug 2022 20:48:02 -0700 (PDT) X-Google-Smtp-Source: AA6agR77AfvgDfhYP1L6DVx/ZciIkJeu4mOvATNwD6si5fK0mh4kUfNdNgxn9Ve0xFqoMjMmYykDpSvmC3EGNMm+dUY= X-Received: by 2002:a05:6870:8901:b0:11d:416d:2ccb with SMTP id i1-20020a056870890100b0011d416d2ccbmr583907oao.176.1661226481986; Mon, 22 Aug 2022 20:48:01 -0700 (PDT) MIME-Version: 1.0 References: <20220819142519.5684-1-mario.limonciello@amd.com> In-Reply-To: From: Kai-Heng Feng Date: Tue, 23 Aug 2022 11:47:50 +0800 Message-ID: Subject: Re: [RFC 0/2] Stop the abuse of Linux-* _OSI strings To: Lyude Paul Cc: Karol Herbst , Mario Limonciello , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rafael@kernel.org, Len Brown , nouveau@lists.freedesktop.org, hdegoede@redhat.com, ddadap@nvidia.com, Dell.Client.Kernel@dell.com, Aaron Ma Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+Cc Aaron] On Tue, Aug 23, 2022 at 5:18 AM Lyude Paul wrote: > > On Fri, 2022-08-19 at 17:44 +0200, Karol Herbst wrote: > > On Fri, Aug 19, 2022 at 4:25 PM Mario Limonciello > > wrote: > > > > > > 3 _OSI strings were introduced in recent years that were intended > > > to workaround very specific problems found on specific systems. > > > > > > The idea was supposed to be that these quirks were only used on > > > those systems, but this proved to be a bad assumption. I've found > > > at least one system in the wild where the vendor using the _OSI > > > string doesn't match the _OSI string and the neither does the use. > > > > > > So this brings a good time to review keeping those strings in the kernel. > > > There are 3 strings that were introduced: > > > > > > Linux-Dell-Video > > > -> Intended for systems with NVIDIA cards that didn't support RTD3 > > > Linux-Lenovo-NV-HDMI-Audio > > > -> Intended for powering on NVIDIA HDMI device > > > Linux-HPI-Hybrid-Graphics > > > -> Intended for changing dGPU output > > > > > > AFAIK the first string is no longer relevant as nouveau now supports > > > RTD3. If that's wrong, this can be changed for the series. > > > > > > > Nouveau always supported RTD3, because that's mainly a kernel feature. > > When those were introduced we simply had a bug only hit on a few > > systems. And instead of helping us to debug this, this workaround was > > added :( We were not even asked about this. > > > > I am a bit curious about the other two though as I am not even sure > > they are needed at all as we put other work arounds in place. @Lyude > > Paul might know more about these. > > Some of the _OSI strings are totally fine. From my recollection: > > [ 0.242993] ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio) > ^ this one is needed to do a couple of ACPI tricks at startup to get the PCIe > device for audio on nvidia's GPU to be detected properly This should be fixed by commit b516ea586d71 ("PCI: Enable NVIDIA HDA controllers"). Aaron worked on more Lenovo systems than me, so he may be more sure of it. > > [ 0.242993] ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics) > > I don't actually know how necessary this is, but I'm hesistant to call this > one bad as it may be related to the funny mux configurations that I'm learning > may exist on HP machines. Should be fixed by commit 8e55f99c510f ("drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops"). And for "Linux-Dell-Video", it should be fixed by 5775b843a619 ("PCI: Restore config space on runtime resume despite being unbound"). So actually I am in favor of removing them all. Kai-Heng > > > > > -- > Cheers, > Lyude Paul (she/her) > Software Engineer at Red Hat >