From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 257AA1F4CA9; Tue, 7 Apr 2026 18:09:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775585374; cv=none; b=m6xdbRhc0Pz9A3IhRqDEq7Qu9p7i4fyTQtdjvSj5tt3FisJ3pN8XSaoo710eifcFE2buNNnY0DEfZQvd29Orz5iR1hQ0RkN7TFIIfUuoPg9W3ukRkIrXZyvq7M/wV1qfmHSP9bDWFSZ0VbU76MkRMU/uPh3rGZ0DSJPFJumw0lI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775585374; c=relaxed/simple; bh=6+TXhFe1ZLkWZlJdqPKfzqrTGxVXq539FFUaAib5kcw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HIOYBhSfpeF9eqfOMlt9LffRKzjs+zLsEYXz08hGOsRuZcKZ7ibyBiAKqG0yHnK7zCfdAkwNuKo+hqGvKzHdwAsirLe9Jpj6YmHoHwvEQJbty2n0D0mzMMkbj2E8KkkEgux1dm4nf8ynhN9R7PcpfHuDHOAw06eJvFtDpxPUJsw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ggWzSJFT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ggWzSJFT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8E86C116C6; Tue, 7 Apr 2026 18:09:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775585374; bh=6+TXhFe1ZLkWZlJdqPKfzqrTGxVXq539FFUaAib5kcw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ggWzSJFTesIwd2YhKNu1ymWX+Ta4kTPTPY/3h9dlBpdCpYSbEFsbI0H7e9rSlT5gs Dao5q1Oa7o6HCCAUXtV9dfxMsY+RSsuhceg6FMyGrDJkgcPprSBxYixpt2oL06fUXR fjuRo2v5yqgnbv1bCJBrEFqu7JP6qlhp1w4VGWAoJt/7Hrhhki1cVd9WNdne4rtWTB tyuXA6AzboaLz0+HNY0y87qaeiqnHvvfAcNZ1m6C4p2aarv/pooDxIA23mF/3H/an3 YzUeOAvZpqtqjMW5M1jIqPurebCAO7fqtckQaFMzzFVE4qnEZeH025Kb6A4AATN2Kk V0UFuhMW9MWcQ== Date: Tue, 7 Apr 2026 13:09:32 -0500 From: "Rob Herring (Arm)" To: Herve Codina Cc: Arnd Bergmann , linux-acpi@vger.kernel.org, Daniel Scally , Charles Keepax , Richard Fitzgerald , Andy Shevchenko , Jonathan Cameron , Fabio Estevam , Dave Jiang , Thomas Petazzoni , Andi Shyti , Ulf Hansson , Saravana Kannan , Ira Weiny , Dan Williams , Steen Hegelund , Linus Walleij , imx@lists.linux.dev, linux-gpio@vger.kernel.org, patches@opensource.cirrus.com, Sakari Ailus , Andrew Lunn , devicetree@vger.kernel.org, Geert Uytterhoeven , linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" , Stephen Boyd , Greg Kroah-Hartman , David Rhodes , Bjorn Helgaas , Conor Dooley , linux-kernel@vger.kernel.org, Luca Ceresoli , Shawn Guo , Vishal Verma , Mark Brown , Davidlohr Bueso , linux-pm@vger.kernel.org, Allan Nielsen , Pengutronix Kernel Team , Wolfram Sang , Len Brown , Sascha Hauer , Danilo Krummrich , Michael Turquette , Frank Li , Krzysztof Kozlowski , driver-core@lists.linux.dev, linux-i2c@vger.kernel.org, linux-sound@vger.kernel.org, Horatiu Vultur , Heikki Krogerus , Kalle Niemi , linux-cxl@vger.kernel.org, Alison Schofield , linux-clk@vger.kernel.org, linux-pci@vger.kernel.org, Matti Vaittinen , Wolfram Sang , linux-spi@vger.kernel.org, Peter Rosin Subject: Re: [PATCH v6 17/27] of: property: Allow fw_devlink device-tree on x86 Message-ID: <177558537013.3212080.6337028648731238779.robh@kernel.org> References: <20260325143555.451852-1-herve.codina@bootlin.com> <20260325143555.451852-18-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260325143555.451852-18-herve.codina@bootlin.com> On Wed, 25 Mar 2026 15:35:44 +0100, Herve Codina wrote: > 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 | 26 +++++++++++++++++++++++++- > 1 file changed, 25 insertions(+), 1 deletion(-) > Applied, thanks!