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 08BA9C433F5 for ; Thu, 6 Jan 2022 00:07:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245752AbiAFAHO (ORCPT ); Wed, 5 Jan 2022 19:07:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245727AbiAFAHN (ORCPT ); Wed, 5 Jan 2022 19:07:13 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40891C061245; Wed, 5 Jan 2022 16:07:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D247A619AC; Thu, 6 Jan 2022 00:07:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC323C36AE9; Thu, 6 Jan 2022 00:07:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641427632; bh=QkmWR8jOZfsoz9AfOFqa0DRvfcUZSPmcIrXXakZWhTg=; h=From:To:Cc:Subject:Date:From; b=bD7l2zPBD+FVFyMhuyn1JR30B2VDAEvl/qVMTbxCtvl1EPvDKaL8x207hCulQRYbD mt5oljuFdWaefcTFn41v/eaPAZt9oiLHSd3VFFBXW5GVrdgJOwCI99XZbRIRQVuww7 PvF0N+rDjzw8XLQ57I1YriLebZ0pzaeq88tQVvWjhpy6H/ZwCv1WU7QG/dA1dcUXbi GESc0dlaGBtF70qBUaxvnVDFZm+hBAXV0bOwJXLcND3S1WaTXtT9GextdVGusVcqer VLS2/8KobZTBqZ4OTNf2f/hI5q2lulO6A+SAL5qBPCsptjVpkczEZK+WvY63fFOr/q nw+4kU7lNyo6Q== From: Bjorn Helgaas To: David Airlie , Daniel Vetter Cc: Xuefeng Li , Huacai Chen , Huacai Chen , linux-pci@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Bjorn Helgaas Subject: [PATCH v8 00/10] vgaarb: Rework default VGA device selection Date: Wed, 5 Jan 2022 18:06:48 -0600 Message-Id: <20220106000658.243509-1-helgaas@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bjorn Helgaas Current default VGA device selection fails in some cases because part of it is done in the vga_arb_device_init() subsys_initcall, and some arches enumerate PCI devices in pcibios_init(), which runs *after* that. For example: - On BMC system, the AST2500 bridge [1a03:1150] does not implement PCI_BRIDGE_CTL_VGA. This is perfectly legal but means the legacy VGA resources won't reach downstream devices unless they're included in the usual bridge windows. - vga_arb_select_default_device() will set a device below such a bridge as the default VGA device as long as it has PCI_COMMAND_IO and PCI_COMMAND_MEMORY enabled. - vga_arbiter_add_pci_device() is called for every VGA device, either at boot-time or at hot-add time, and it will also set the device as the default VGA device, but ONLY if all bridges leading to it implement PCI_BRIDGE_CTL_VGA. - This difference between vga_arb_select_default_device() and vga_arbiter_add_pci_device() means that a device below an AST2500 or similar bridge can only be set as the default if it is enumerated before vga_arb_device_init(). - On ACPI-based systems, PCI devices are enumerated by acpi_init(), which runs before vga_arb_device_init(). - On non-ACPI systems, like on MIPS system, they are enumerated by pcibios_init(), which typically runs *after* vga_arb_device_init(). This series consolidates all the default VGA device selection in vga_arbiter_add_pci_device(), which is always called after enumerating a PCI device. Almost all the work here is Huacai's. I restructured it a little bit and added a few trivial patches on top. I'd like to move vgaarb.c to drivers/pci eventually, but there's another initcall ordering snag that needs to be resolved first, so this leaves it where it is. Bjorn Version history: V0 original implementation as final quirk to set default device. https://lore.kernel.org/r/20210514080025.1828197-6-chenhuacai@loongson.cn V1 rework vgaarb to do all default device selection in vga_arbiter_add_pci_device(). https://lore.kernel.org/r/20210705100503.1120643-1-chenhuacai@loongson.cn V2 move arbiter to PCI subsystem, fix nits. https://lore.kernel.org/r/20210722212920.347118-1-helgaas@kernel.org V3 rewrite the commit log of the last patch (which is also summarized by Bjorn). https://lore.kernel.org/r/20210820100832.663931-1-chenhuacai@loongson.cn V4 split the last patch to two steps. https://lore.kernel.org/r/20210827083129.2781420-1-chenhuacai@loongson.cn V5 split Patch-9 again and sort the patches. https://lore.kernel.org/r/20210911093056.1555274-1-chenhuacai@loongson.cn V6 split Patch-5 again and sort the patches again. https://lore.kernel.org/r/20210916082941.3421838-1-chenhuacai@loongson.cn V7 stop moving vgaarb to drivers/pci because of ordering issues with misc_init(). https://lore.kernel.org/r/20211015061512.2941859-1-chenhuacai@loongson.cn https://lore.kernel.org/r/CAAhV-H7FhAjM-Ha42Z1dLrE4PvC9frfyeU27KHWcyWKkMftEsA@mail.gmail.com Bjorn Helgaas (8): vgaarb: Factor out vga_select_framebuffer_device() vgaarb: Factor out default VGA device selection vgaarb: Move framebuffer detection to ADD_DEVICE path vgaarb: Move non-legacy VGA detection to ADD_DEVICE path vgaarb: Move disabled VGA device detection to ADD_DEVICE path vgaarb: Remove empty vga_arb_device_card_gone() vgaarb: Use unsigned format string to print lock counts vgaarb: Replace full MIT license text with SPDX identifier Huacai Chen (2): vgaarb: Move vga_arb_integrated_gpu() earlier in file vgaarb: Log bridge control messages when adding devices drivers/gpu/vga/vgaarb.c | 311 +++++++++++++++++++-------------------- 1 file changed, 154 insertions(+), 157 deletions(-) -- 2.25.1