From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95F383195E7; Wed, 15 Oct 2025 07:20:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760512809; cv=none; b=tYHHy54F9wrab3uLHCBzzwFvZ8uocsHtBjVNMNqV7TDxSknK6K8T8Bf3bUhnRayGMeJEY3+DwWTHVPlYjjCRvV+njRvfwenf5meLfgGKO0bnNakbFJnepGvOEhuSTBV9uftH/8HNLRWRTSmvriz3/03thmkrFfisSc+PmwjhsQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760512809; c=relaxed/simple; bh=9ttrNVLkRsSDRCfmp+OkyIDylFexNXHYFc3MB2ymOjI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EOhG9dopTCb3yUOMizMO1jkvDjifT8gJLmOi0F6W+GuicKF5tNpc6BthqEmnUu+kuWDbRA2prpION2o3ZaOa15EuYh4+9u7TxHi2k8pagw3o4iRUYvEjs0k6tyUhO5IMNxBo4jawy7rFJMfl7Mrv9ltuldS93ZUKmQA2HQ/5Mok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=HY/Ttvr1; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="HY/Ttvr1" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 510431A13AA; Wed, 15 Oct 2025 07:20:06 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 235E7606F9; Wed, 15 Oct 2025 07:20:06 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 41F8E102F22AF; Wed, 15 Oct 2025 09:19:50 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1760512803; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=9R3lRfdbM4+6S/Dlp2yQbInaGSHf0B0yRJSd8+1498s=; b=HY/Ttvr1IjR23UPcv6L80wsat+zSo70BPXFe2JJkRJx83N8zJLFXvHKXV93+3Cbm7FKknb QyTsxyzeHPmqhLnoFqaElb7jCC+aVWuUJ/+ozqJvNi9wmGEMtRkAgkWUfgXryzITK4SoVZ c1nU0iaw9WiNNb2GkbjD8fG9wcc8d+lIQl67udR5iBpTAf1F+1Bz91eEAS92c0MXBifrPr 7aybsOiGNOTrtTfGphFRpr3hO5lGP4lLR1xfxVl9lI6q8l1NwJWODoowB7XRsyS0vUcA2R uKzGkc41CtLI4pfBHHhD4Y+5t2m/blWt2UfvIANhfA/cTwhOqX5kRpSkfjAQkQ== From: Herve Codina To: Andrew Lunn , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Michael Turquette , Stephen Boyd , Andi Shyti , Wolfram Sang , Peter Rosin , Arnd Bergmann , Herve Codina , Saravana Kannan , Bjorn Helgaas , Charles Keepax , Richard Fitzgerald , David Rhodes , Linus Walleij , Ulf Hansson , Mark Brown , Andy Shevchenko , Daniel Scally , Heikki Krogerus , Sakari Ailus , Len Brown , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Ira Weiny , Dan Williams , Geert Uytterhoeven Cc: Wolfram Sang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-i2c@vger.kernel.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, patches@opensource.cirrus.com, linux-gpio@vger.kernel.org, linux-pm@vger.kernel.org, linux-spi@vger.kernel.org, linux-acpi@vger.kernel.org, linux-cxl@vger.kernel.org, Allan Nielsen , Horatiu Vultur , Steen Hegelund , Luca Ceresoli , Thomas Petazzoni Subject: [PATCH v4 19/29] of: property: Allow fw_devlink device-tree on x86 Date: Wed, 15 Oct 2025 09:14:06 +0200 Message-ID: <20251015071420.1173068-20-herve.codina@bootlin.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251015071420.1173068-1-herve.codina@bootlin.com> References: <20251015071420.1173068-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 PCI drivers can use a device-tree overlay to describe the hardware available on the PCI board. This is the case, for instance, of the LAN966x PCI device driver. Adding some more nodes in the device-tree overlay adds some more consumer/supplier relationship between devices instantiated from this overlay. Those fw_node consumer/supplier relationships are handled by fw_devlink and are created based on the device-tree parsing done by the of_fwnode_add_links() function. Those consumer/supplier links are needed in order to ensure a correct PM runtime management and a correct removal order between devices. For instance, without those links a supplier can be removed before its consumers is removed leading to all kind of issue if this consumer still want the use the already removed supplier. The support for the usage of an overlay from a PCI driver has been added on x86 systems in commit 1f340724419ed ("PCI: of: Create device tree PCI host bridge node"). In the past, support for fw_devlink on x86 had been tried but this support has been removed in commit 4a48b66b3f52 ("of: property: Disable fw_devlink DT support for X86"). Indeed, this support was breaking some x86 systems such as OLPC system and the regression was reported in [0]. Instead of disabling this support for all x86 system, use a finer grain and disable this support only for the possible problematic subset of x86 systems (at least OLPC and CE4100). Those systems use a device-tree to describe their hardware. Identify those systems using key properties in the device-tree. Signed-off-by: Herve Codina Link: https://lore.kernel.org/lkml/3c1f2473-92ad-bfc4-258e-a5a08ad73dd0@web.de/ [0] --- drivers/of/property.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/of/property.c b/drivers/of/property.c index c1feb631e383..09b568e3b826 100644 --- a/drivers/of/property.c +++ b/drivers/of/property.c @@ -1600,12 +1600,41 @@ static int of_fwnode_irq_get(const struct fwnode_handle *fwnode, return of_irq_get(to_of_node(fwnode), index); } +static int match_property_by_path(const char *node_path, const char *prop_name, + const char *value) +{ + struct device_node *np __free(device_node) = of_find_node_by_path(node_path); + + return of_property_match_string(np, prop_name, value); +} + +static bool of_is_fwnode_add_links_supported(void) +{ + static int is_supported = -1; + + if (is_supported != -1) + return !!is_supported; + + if (match_property_by_path("/soc", "compatible", "intel,ce4100-cp") >= 0) + goto not_supported; + + if (match_property_by_path("/", "architecture", "OLPC") >= 0) + goto not_supported; + + is_supported = 1; + return !!is_supported; + +not_supported: + is_supported = 0; + return !!is_supported; +} + static int of_fwnode_add_links(struct fwnode_handle *fwnode) { const struct property *p; struct device_node *con_np = to_of_node(fwnode); - if (IS_ENABLED(CONFIG_X86)) + if (IS_ENABLED(CONFIG_X86) && !of_is_fwnode_add_links_supported()) return 0; if (!con_np) -- 2.51.0