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 21286C433EF for ; Mon, 10 Jan 2022 17:13:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238055AbiAJRNW (ORCPT ); Mon, 10 Jan 2022 12:13:22 -0500 Received: from mga12.intel.com ([192.55.52.136]:42399 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238007AbiAJRNU (ORCPT ); Mon, 10 Jan 2022 12:13:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1641834800; x=1673370800; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=rFpO3idGkMwxHuRUVjKYhHQ355NihZqo1GVyZknlLlY=; b=JLgBQB0UT745Bt64RjTbE7bCFTctEftjZ4U+JuB8sfEnPdeEeLDw5Gss rFQTzRFAAxkBTI6wmLj4fVgds5JLvW0HU69obJ3chPOexErqG/5wPNBI7 y/j1ABu0foN+GW3c92eKqkAmWwXFl574wyODXsu3h/2K7dqUgEQlgYBR9 niThg3Yjubxt8pTnkC/mOORRoSL1o0K6nJr1B7Yo4zJgBWNrSBDYE2gKG wRe44mBIT8SW3V5ADn1HMk8YrV8gNpwczL2bNP1YEnmP/P885lnz2sHls 990MI5Q8KlapHLMK8q+mG9YeIt/iIqcSr2R209ppJSw6YBm3Q2PUGHtCi Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10222"; a="223254331" X-IronPort-AV: E=Sophos;i="5.88,277,1635231600"; d="scan'208";a="223254331" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jan 2022 09:11:40 -0800 X-IronPort-AV: E=Sophos;i="5.88,277,1635231600"; d="scan'208";a="528351871" Received: from ryanjor-mobl.amr.corp.intel.com (HELO intel.com) ([10.255.36.174]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jan 2022 09:11:37 -0800 Date: Mon, 10 Jan 2022 12:11:36 -0500 From: Rodrigo Vivi To: Bjorn Helgaas Cc: Lucas De Marchi , Dave Hansen , linux-pci@vger.kernel.org, intel-gfx@lists.freedesktop.org, x86@kernel.org, Ingo Molnar , Bjorn Helgaas , Thomas Gleixner Subject: Re: [Intel-gfx] [PATCH v3 3/3] x86/quirks: Fix stolen detection with integrated + discrete GPU Message-ID: References: <20220107210516.907834-3-lucas.demarchi@intel.com> <20220108025732.GA443415@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220108025732.GA443415@bhelgaas> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jan 07, 2022 at 08:57:32PM -0600, Bjorn Helgaas wrote: > On Fri, Jan 07, 2022 at 01:05:16PM -0800, Lucas De Marchi wrote: > > early_pci_scan_bus() does a depth-first traversal, possibly calling > > the quirk functions for each device based on vendor, device and class > > from early_qrk table. intel_graphics_quirks() however uses PCI_ANY_ID > > and does additional filtering in the quirk. > > > > If there is an Intel integrated + discrete GPU the quirk may be called > > first for the discrete GPU based on the PCI topology. Then we will fail > > to reserve the system stolen memory for the integrated GPU, because we > > will already have marked the quirk as "applied". > > > > This was reproduced in a setup with Alderlake-P (integrated) + DG2 > > (discrete), with the following PCI topology: > > > > - 00:01.0 Bridge > > `- 03:00.0 DG2 > > - 00:02.0 Integrated GPU > > > > Move the setting of quirk_applied in intel_graphics_quirks() so it's > > mark as applied only when we find the integrated GPU based on the > > intel_early_ids table. > > > > Signed-off-by: Lucas De Marchi > > I don't know the details of stolen memory, but the implementation of > this quirk looks good to me. Very nice that it's now very clear > exactly what the change is. Reviewed-by: Rodrigo Vivi Bjorn, ack to merge through drm-intel? > > > --- > > > > v3: now that we do the refactor before the fix, we can do a single line > > change to fix intel_graphics_quirks(). Also, we don't change > > intel_graphics_stolen() anymore as we did in v2: we don't have to check > > other devices anymore if there was a previous match causing > > intel_graphics_stolen() to be called (there can only be one integrated > > GPU reserving the stolen memory). > > > > arch/x86/kernel/early-quirks.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c > > index df34963e23bf..932f9087c324 100644 > > --- a/arch/x86/kernel/early-quirks.c > > +++ b/arch/x86/kernel/early-quirks.c > > @@ -609,8 +609,6 @@ static void __init intel_graphics_quirks(int num, int slot, int func) > > if (quirk_applied) > > return; > > > > - quirk_applied = true; > > - > > device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID); > > > > for (i = 0; i < ARRAY_SIZE(intel_early_ids); i++) { > > @@ -623,6 +621,8 @@ static void __init intel_graphics_quirks(int num, int slot, int func) > > > > intel_graphics_stolen(num, slot, func, early_ops); > > > > + quirk_applied = true; > > + > > return; > > } > > } > > -- > > 2.34.1 > >