From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [217.70.183.195]) (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 6ECCA79FE; Wed, 8 Jan 2025 09:47:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736329647; cv=none; b=CZmxmTAnqAFMYkskWBJ4d/n1xqdG6svJt/rIg8Q5cS8LGsuFqRAj8Q3NAi6ADppOHB9aJ0fleN3rGxvtRKJ0+puqZeAKPOhtx8B9wdqx1F7EsY1wZR9Cw8nBDAdopw7Wmpq66u+hwm//2r5gVgLhGwn+IWQ7ROGbF7YJ8Z0lJgY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736329647; c=relaxed/simple; bh=1D7ZC0rHwNo/nas3TA0kqG1f7+uEOZG4Yl5PtuHZDXk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=EheYSoAd74grFLUhjg1Ll9/ovkLZPEvQ+bLUHUnPxdagKM6A0G9gx7JTS0Wowl6HvVc8GTjunKFWj0q3CvMSTiG4G+som9pv9OoX3P0bDZCn8NBFE7UmqlGXVR9s63oN3X9DeHlwWTizj3TeUhC+hteUnprG97/7mwq2Tyti2VE= 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=iZIO5axX; arc=none smtp.client-ip=217.70.183.195 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="iZIO5axX" Received: by mail.gandi.net (Postfix) with ESMTPSA id 2786460003; Wed, 8 Jan 2025 09:47:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736329643; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dt3WALCVLJCRW2cde7nrz+vlEW88l2pHvW21cOkQCWE=; b=iZIO5axXsc/E5bA8k613vrh/0SQXeF8McKHH2Q/SJZYE+zWwFrhm8hNH0vsfZ2ZIRlbxlE DWCNgQdDUNO7v6Nz4f1HoNiefjy57JGhiz8UTjkD4HZW6MX0GaEm6c+Ab3Hrc2Ahn8O2R0 10fyRgYSbGZVSNF2uCGSRESH+t3C1pAKkRzYI8/0nk5Gb2baoPmbb9rLiQsMecA4M2sseo mPP6jN7xbKGitxvqgzgTzBEQ57n1kdyQJugDKeDzN/3B5VOc4NkqWM5Q/k4j3jIaXnCjJy APt/tU5OvkUF/7mJgAAzpRtRWCUpNqKJSlwXfEDGmGTEmrX3AzUixBnkAFyfwg== Date: Wed, 8 Jan 2025 10:47:19 +0100 From: Herve Codina To: Ayush Singh Cc: Andrew Davis , Geert Uytterhoeven , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Arnd Bergmann , Greg Kroah-Hartman , Saravana Kannan , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Luca Ceresoli , Thomas Petazzoni , David Gibson Subject: Re: [PATCH 0/7] of: overlay: Add support for export-symbols node feature Message-ID: <20250108104719.0412ad94@bootlin.com> In-Reply-To: References: <20241209151830.95723-1-herve.codina@bootlin.com> <33c61b28-c0b8-478d-8107-c6ed1ff9e466@beagleboard.org> <20241210104141.39acffb1@bootlin.com> <20241210115515.1886f73f@bootlin.com> <6d48095d-59b1-4439-8e2a-927aa1aa1b55@beagleboard.org> <20250108090750.45685a50@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) 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=UTF-8 Content-Transfer-Encoding: 8bit X-GND-Sasl: herve.codina@bootlin.com Hi Ayush, On Wed, 8 Jan 2025 13:58:04 +0530 Ayush Singh wrote: ... > > I will experiment with adding support to dtc and see how things look. > Hopefully, 2025 is the year of addon board support. > Also one point different between fdtoverlay an runtime loading is that runtime loading allows to set the target node of the overlay at runtime. For instance, on LAN966X PCI driver, an overlay is loaded and applied on a PCI device node. The overlay loading is done by the PCI driver device: https://elixir.bootlin.com/linux/v6.13-rc1/source/drivers/misc/lan966x_pci.c#L131 The overlay loaded is the following one: https://elixir.bootlin.com/linux/v6.13-rc1/source/drivers/misc/lan966x_pci.dtso For addon boards, this feature is also useful because without any modification in the overlay itself, it can be applied on the correct connector. This allows to support, without any overlay modification the following cases: - A base board with multiple connectors where an addon board can be connected. - An addon board with its own DT overlay used on different base board This feature is not supported by fdtoverlay. Maybe something like fdtoverlay --base=/somewhere/my_connector could be implemented in fdtoverlay in order to choose the node where the overlay has to be applied. Best regards, Hervé