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 CC2E9316917; Fri, 19 Dec 2025 15:25:29 +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=1766157929; cv=none; b=LwsGcTu7+s1v7Qj9I+kxTPss1eELkIaxsmy9Org1Paw8rx1buVoZIum273MsXCPVGI40yBSGf/rhFsjxAizsQjwsziWVac3ofekIeBsIqlNO5oVeLk5y1JuBO4UHoBPHqtmafB8pDB4tlHAJ+OW7Ag63DVZFffPSlOg0YlFGaI0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766157929; c=relaxed/simple; bh=b7ZQFUmybQOKOhzGs8UkdT5AC/ICY2hLdh/vjkXWyaA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bLNfqNOTEPA8NQgvi/4Qy+Uj44iih+zscgYGlD91FR3+egCGU/qBvfL6tvOmJ0TZMq5XCvoYCW64l8vt/EGvahH8HD08d3ohhaPVTjxEycvfRGmVc/qNhnHt1oEuDUZw+Vy/0MFgZUuG1wHY1T60d1hZjaApmbWbZ4qvMn9uAbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RXdQBjNe; 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="RXdQBjNe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CBE9C4CEF1; Fri, 19 Dec 2025 15:25:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766157929; bh=b7ZQFUmybQOKOhzGs8UkdT5AC/ICY2hLdh/vjkXWyaA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RXdQBjNeX/Bqk7SOAQ72GTn3XZquDe5oklsreC30NWFztnWgXtzQSwF9jGWbVn/I6 7Hh5EkuMS+vQpFwkPmzBV/PNP+2hu1UlCpDlwGni6IP1a56PJCHV4xFHtj3ahvfIPl thEwGdmZNBh1oXSr5lMQeVpJy3763/VIA8VtKdQQYSItwyL6JJd0fit0SKrAXZkszI +i1AuoFPa1FaJ+F0MC/l1g+D3pUXdm6rUK2dpjyBfkbSVaE82+H+ffmY3Gg6Jf7Oev suyBS6/QJH9dyyTzLZVYVOZ9EKRUdjCiGXTKGj6PKIQja/M15mChjIqq5EYrn79+V/ SL75hkgARsRQg== Date: Fri, 19 Dec 2025 09:25:26 -0600 From: Rob Herring To: Andrea della Porta Cc: Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , Broadcom internal kernel review list , Bjorn Helgaas , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, iivanov@suse.de, svarbanov@suse.de, mbrugger@suse.com, Phil Elwell Subject: Re: [PATCH 0/4] Fix RP1 DeviceTree hierarchy and drop overlay support Message-ID: <20251219152526.GA3333129-robh@kernel.org> References: Precedence: bulk X-Mailing-List: linux-kernel@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: On Thu, Dec 18, 2025 at 08:09:05PM +0100, Andrea della Porta wrote: > The current RP1 implementation is plagued by several issues, as follows: > > - the node name for RP1 is too specific and should be generic instead > (see [1]). > > - the fully defined DTS has its PCI hierarchy wrongly described. There > should be a PCI root port between the root complex and the endpoint > (see [1]). > > - since CONFIG_PCI_DYNAMIC_OF_NODES can be dropped in the future > becoming an automatically enabled feature, it would be wise to not > depend on it (see [2]). > > - overlay support has led to a lot of confusion. It's not really usable > right now and users are not even used to it (see [3]). > > This patch aims at solving the aforementioned problems by amending the > PCI topology as follows: > > ... > pcie@1000120000 { > ... > > pci@0,0 { > device_type = "pci"; > reg = <0x00 0x00 0x00 0x00 0x00>; > ... > > dev@0,0 { > compatible = "pci1de4,1"; > reg = <0x10000 0x00 0x00 0x00 0x00>; > ... > > pci-ep-bus@1 { > compatible = "simple-bus"; > ... > > /* peripherals child nodes */ > }; > }; > }; > }; > > The reg property is important since it permits the binding the OF > device_node structure to the pci_dev, encoding the BDF in the upper > portion of the address. > > This patch also drops the overlay support in favor of the fully > described DT while streamlining it as a result. > > Links: > [1] - https://lore.kernel.org/all/aTvz_OeVnciiqATz@apocalypse/ > [2] - https://lore.kernel.org/all/CAL_JsqJUzB71QdMcxJtNZ7raoPcK+SfTh7EVzGmk=syo8xLKQw@mail.gmail.com/ > [3] - https://lore.kernel.org/all/CAL_JsqJUzB71QdMcxJtNZ7raoPcK+SfTh7EVzGmk=syo8xLKQw@mail.gmail.com/ > > Andrea della Porta (4): > dt-bindings: misc: pci1de4,1: add required reg property for endpoint > misc: rp1: drop overlay support > arm64: dts: broadcom: bcm2712: fix RP1 endpoint PCI topology > arm64: dts: broadcom: rp1: drop RP1 overlay Thanks for doing this. Reviewed-by: Rob Herring