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 49BF71C84D5; Wed, 11 Jun 2025 15:48:24 +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=1749656905; cv=none; b=Td1+gKQhdjsuBw3plHig6FA/9hFDi3qsEuqaQ8rmk2VkMcbaIVWGLqev5CQgHECnVGeziNo1g+BuMAQ+2gZ6q/vF0KZd4Maac8PAkF6KeJapeXpPJmQLCRHOTccx6cg8B8DCSFpXk3PYBdqA8DBLgq0hXM7DMXx+VnAs6kbQAjU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749656905; c=relaxed/simple; bh=LNb7YbVus4nbWzU8eQUbtfq2tisE72p1WUOPyk88UIk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uet0tD4MMdPK7cnORY6lgxFjm91bA6TllJERkY+nQwpodDDvIGoTrgpm7DcNx3ZKcbrXRkT7MOFNkX31ZtRfyYKnZ8s9qu4q2n0Y8YoSc50ziWtu8XlG517jl+arXbvODtPrmKlzR97OdHnBVT5R0tgaIZD1454SArBkiHTV+9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eZvumMgG; 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="eZvumMgG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE600C4CEE3; Wed, 11 Jun 2025 15:48:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749656904; bh=LNb7YbVus4nbWzU8eQUbtfq2tisE72p1WUOPyk88UIk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=eZvumMgGK6SbKsBcFzKeJeRL43GMbesaZDPm1UXUDNwThKkF01+7651Besemd7NH2 34NbeyYs5sWouLFZhNHPlI5XpHwcTBwxHUpHhYBMjpjedaD1ebRHaJi2pey9UAPTyR Ngi7JRognCRZZlA0LQ+z1b2lox/5DpFv/NL0rJTQZ30SAk0HZjKuBrY03kfJFmLABa 8DV62B14yT1S+bH3EwHdijXQWb7ssNnzBqIkGD1/whEbYQQn0pjemfMbtjsL2qnyQD Hg9tfh9Ti5kYg0KYU0XuLZY2LSjCzS1v7jb41B5+N13etyPHnXU22FpVen9/iJKTbc OLVwzEraB/MzA== Message-ID: Date: Wed, 11 Jun 2025 17:48:20 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 5/9] ARM: dts: stm32: add Hardware debug port (HDP) on stm32mp13 To: Clement LE GOFFIC , Linus Walleij , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Maxime Coquelin , Alexandre Torgue , Bartosz Golaszewski Cc: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org References: <20250523-hdp-upstream-v3-0-bd6ca199466a@foss.st.com> <20250523-hdp-upstream-v3-5-bd6ca199466a@foss.st.com> <5b7a2102-ff68-4aab-a88d-0c4f9195ef95@kernel.org> <3c868c4b-8a0e-44b5-9d6e-3a0526d9deeb@foss.st.com> <3ba588ed-1614-4877-b6fc-b5aa853b8c2e@kernel.org> <714ad17d-53f1-4703-8e13-61c290a8da89@foss.st.com> <7000f63e-5e68-465d-9d7f-1a6ca0524222@kernel.org> <42a0b7ab-d85d-4d52-a263-4a4648c7ff05@kernel.org> <2865ab3a-1c20-4951-8132-4be98d73d70e@foss.st.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/06/2025 16:08, Clement LE GOFFIC wrote: > On 6/11/25 08:35, Krzysztof Kozlowski wrote: >> On 10/06/2025 15:33, Clement LE GOFFIC wrote: >>> On 6/10/25 14:38, Krzysztof Kozlowski wrote: >>>> On 10/06/2025 14:02, Clement LE GOFFIC wrote: >>>>> On 5/29/25 11:01, Krzysztof Kozlowski wrote: >>>>>> On 28/05/2025 14:14, Clement LE GOFFIC wrote: >>>>>>>> >>>>>>>>> + }; >>>>>>>>> + >>>>>>>>> + hdp: pinctrl@5002a000 { >>>>>>>>> + compatible = "st,stm32mp131-hdp"; >>>>>>>>> + reg = <0x5002a000 0x400>; >>>>>>>>> + clocks = <&rcc HDP>; >>>>>>>>> status = "disabled"; >>>>>>>> >>>>>>>> Why are you disabling it? What is missing? >>>>>>> >>>>>>> Nothing is missing just disabled by default. >>>>>>> The node is then enabled when needed in board's dts file. >>>>>> Nodes should not be disabled by default if they are complete. That's why >>>>>> I asked what is missing. Drop. >>>>> >>>>> Hi Krzysztof, OK I better understand now. >>>>> So yes the 'pinctrl-*' properties which are board dependent are lacking. >>>> >>>> These are not properties of this node. >>> >>> Does this mean I should add 'pinctrl-*' properties in bindings yaml file ? >>> I don't get it.. >> >> These properties have no meaning here, so the hardware description is >> complete. You claim that you miss them thus device is incomplete is just >> not correct: these properties do not belong here! They belong to the >> board but even there they are totally optional. Why would they be a >> required resource? >> >> To remind: we talk here ONLY about required resources. > > Yes, 'pinctrl-*' properties belongs to the board and are not required. > So nothing is missing. > > This hdp node in the SoC dtsi file can be enabled by default. > But the hdp driver will probe and do nothing because without the > 'pinctrl-*' properties from the board files it would not be able to > access to any pin. Pinctrl has other features in general, including interfaces to userspace (as pretty often combined with gpio, although not sure if relevant here). > I consider enabling this driver by default in SoC dtsi file as just > increasing the boot time on "every" board. > It's the board dts that requires the hdp and provides the 'pinctrl-*' > properties to connect the hdp to some SoC pin and then to some signal on > the board. For me it's natural to have the status okay only in the board > dts file. The DTS is not the way to optimize boot processes. It is OS-independent hardware description. My BSD system for example uses smart driver which avoids probing, but also my user-space needs this device to talk over exposed interface, so why choice of Linux probing should affect others? Best regards, Krzysztof