From patchwork Mon Jan 9 20:57:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 640956 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 6667CC5479D for ; Mon, 9 Jan 2023 21:05:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237718AbjAIVFX (ORCPT ); Mon, 9 Jan 2023 16:05:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237857AbjAIVE7 (ORCPT ); Mon, 9 Jan 2023 16:04:59 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 805778B523 for ; Mon, 9 Jan 2023 12:57:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673297847; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JxivtNO15kfEhXSMYwuZ/uLbnXccY2i9uozRcRx7JYc=; b=DGImgxgr/PC53hsS7rVFVKgVSezQI6Q/nSsImrIZGKPHuXUe46VklSAA38C5cD29lPe4sb q2GvUNM8fMBkBmT+8dk6dXRmpPF+LpfHZwW+nWyqOXR8MN6fLYYXyLvPHBj82GkrsUe3yR g1Hnvw9imoE/W3OnHBA4RR0j5AWzSis= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-153-UzuVsKOeMEaDeUoAKvhHjA-1; Mon, 09 Jan 2023 15:57:24 -0500 X-MC-Unique: UzuVsKOeMEaDeUoAKvhHjA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DF0E93804066; Mon, 9 Jan 2023 20:57:23 +0000 (UTC) Received: from shalem.redhat.com (unknown [10.39.192.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id A6081492B00; Mon, 9 Jan 2023 20:57:22 +0000 (UTC) From: Hans de Goede To: Jani Nikula , "Rafael J . Wysocki" , Mika Westerberg Cc: Hans de Goede , intel-gfx , dri-devel@lists.freedesktop.org, Len Brown , linux-acpi@vger.kernel.org Subject: [PATCH] ACPI: Fix selecting the wrong ACPI fwnode for the iGPU on some Dell laptops Date: Mon, 9 Jan 2023 21:57:21 +0100 Message-Id: <20230109205721.60694-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org The Dell Latitude E6430 both with and without the optional NVidia dGPU has a bug in its ACPI tables which is causing Linux to assign the wrong ACPI fwnode / companion to the pci_device for the i915 iGPU. Specifically under the PCI root bridge there are these 2 ACPI Device()s : Scope (_SB.PCI0) { Device (GFX0) { Name (_ADR, 0x00020000) // _ADR: Address } ... Device (VID) { Name (_ADR, 0x00020000) // _ADR: Address ... Method (_DOS, 1, NotSerialized) // _DOS: Disable Output Switching { VDP8 = Arg0 VDP1 (One, VDP8) } Method (_DOD, 0, NotSerialized) // _DOD: Display Output Devices { ... } ... } } The non-functional GFX0 ACPI device is a problem, because this gets returned as ACPI companion-device by acpi_find_child_device() for the iGPU. This is a long standing problem and the i915 driver does use the ACPI companion for some things, but works fine without it. However since commit 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") acpi_get_pci_dev() relies on the physical-node pointer in the acpi_device and that is set on the wrong acpi_device because of the wrong acpi_find_child_device() return. This breaks the ACPI video code, leading to non working backlight control in some cases. Make find_child_checks() return a higher score for children which have pnp-ids set by various scan helpers like acpi_is_video_device(), so that it picks the right companion-device. An alternative approach would be to directly call acpi_is_video_device() from find_child_checks() but that would be somewhat computationally expensive given that acpi_find_child_device() iterates over all the PCI0 children every time it is called. Fixes: 63f534b8bad9 ("ACPI: PCI: Rework acpi_get_pci_dev()") Signed-off-by: Hans de Goede --- drivers/acpi/glue.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c index 204fe94c7e45..2055dfd7678b 100644 --- a/drivers/acpi/glue.c +++ b/drivers/acpi/glue.c @@ -75,7 +75,7 @@ static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) } #define FIND_CHILD_MIN_SCORE 1 -#define FIND_CHILD_MAX_SCORE 2 +#define FIND_CHILD_MAX_SCORE 3 static int match_any(struct acpi_device *adev, void *not_used) { @@ -89,15 +89,25 @@ static bool acpi_dev_has_children(struct acpi_device *adev) static int find_child_checks(struct acpi_device *adev, bool check_children) { + int score = FIND_CHILD_MIN_SCORE; unsigned long long sta; acpi_status status; if (check_children && !acpi_dev_has_children(adev)) return -ENODEV; + /* + * For devices without a _STA method, prefer devices without a _HID + * (which conflicts with having an _ADR) but which have been matched + * in some other way, like e.g. by acpi_is_video_device() over devices + * with no ids at all. + */ + if (!adev->pnp.type.platform_id && adev->pnp.type.hardware_id) + score++; + status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); if (status == AE_NOT_FOUND) - return FIND_CHILD_MIN_SCORE; + return score; if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) return -ENODEV;