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 C49D736D4FC; Wed, 3 Dec 2025 11:24:34 +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=1764761074; cv=none; b=YuRBm1Rxtf2oUU2xbWsoaqPoG9F0vb06l7ZR+m5V7rS8NsOxMDYxc5jW6ITpZfbXXgn+qvm5ohjkX+6IEQUrrLGJ8TbVL2SyhdyC9X5lFsWhzTvAcsj9uTzkzV9EEz6z71BKIn2n6p2/Npw8KoNSUxpWVHnoca7/vOi2qq26bvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764761074; c=relaxed/simple; bh=7vp81gq/AzlQ2ezHN6rqzTadSfhvSo+POlhzPIKyWKc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Gx5gcRt/92kGodw9dIbndXb3zpajq/eut5mVfG36+Rrz4Di9tOOthJsoGAPYjpCuWZ26axxTHWyL31vG6d9YjmC9u2/wFyvN6f1RqkBywkPS4Go88CabHDoHScC21SB/aCZl5xPOQ5VDEPwY7DB5SspAE1b0ABP0P53AjFowLLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z9bmUHSQ; 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="Z9bmUHSQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 029EAC4CEFB; Wed, 3 Dec 2025 11:24:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764761074; bh=7vp81gq/AzlQ2ezHN6rqzTadSfhvSo+POlhzPIKyWKc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Z9bmUHSQCgS1EiWqR7TwE+4V+JhqphP336m2o9ynrUqfKEJSWPTgjiavWGAYOyJCt 91uFGwAHrnhVhtB/Pbv66vKKMmxXcpeWUqqjbOFqUudMmg3Wrqpu4wVS9CM3sXq698 tgjprP92lFfZddI0saHWudc2I5z4ebqfjK8zQ2J8wlhpnomPULWD8NkiXlHa6BDYW0 sTx7Mg8IXwYTcd3suIQEd6Fwb9VLQ0dtGRhUNLrAgd2SKzVYZG0fKseeUp4Z8bF3Hm +VXf4LHQDhOBvxwQnO6MVlE0YOfklf11MbVxneJDDZghMOGo6Xw1otLnB22eJw4bLu NaU29iirPb7Bw== Message-ID: Date: Wed, 3 Dec 2025 12:24:30 +0100 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: SoC-specific device tree aliases? To: Marc Kleine-Budde Cc: Ahmad Fatoum , Rob Herring , Sascha Hauer , "devicetree@vger.kernel.org" , Conor Dooley , devicetree-spec@vger.kernel.org, quentin.schulz@cherry.de, Marc Kleine-Budde , "kernel@pengutronix.de" , Krzysztof Kozlowski References: <20251117-smooth-spiked-loon-52df28-mkl@pengutronix.de> <576a9eae-7dba-47d0-ad66-0a81d1893271@kernel.org> <9e14fb8e-af84-4072-b0ac-9ead882782be@kernel.org> <07ee3540-d0c1-436e-9e1d-db1952f609a6@kernel.org> <6638e499-2320-41c9-b720-faf4f976e476@kernel.org> <20251203-adorable-gila-monster-3d313a-mkl@blackshift.org> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; keydata= xsFNBFVDQq4BEAC6KeLOfFsAvFMBsrCrJ2bCalhPv5+KQF2PS2+iwZI8BpRZoV+Bd5kWvN79 cFgcqTTuNHjAvxtUG8pQgGTHAObYs6xeYJtjUH0ZX6ndJ33FJYf5V3yXqqjcZ30FgHzJCFUu JMp7PSyMPzpUXfU12yfcRYVEMQrmplNZssmYhiTeVicuOOypWugZKVLGNm0IweVCaZ/DJDIH gNbpvVwjcKYrx85m9cBVEBUGaQP6AT7qlVCkrf50v8bofSIyVa2xmubbAwwFA1oxoOusjPIE J3iadrwpFvsZjF5uHAKS+7wHLoW9hVzOnLbX6ajk5Hf8Pb1m+VH/E8bPBNNYKkfTtypTDUCj NYcd27tjnXfG+SDs/EXNUAIRefCyvaRG7oRYF3Ec+2RgQDRnmmjCjoQNbFrJvJkFHlPeHaeS BosGY+XWKydnmsfY7SSnjAzLUGAFhLd/XDVpb1Een2XucPpKvt9ORF+48gy12FA5GduRLhQU vK4tU7ojoem/G23PcowM1CwPurC8sAVsQb9KmwTGh7rVz3ks3w/zfGBy3+WmLg++C2Wct6nM Pd8/6CBVjEWqD06/RjI2AnjIq5fSEH/BIfXXfC68nMp9BZoy3So4ZsbOlBmtAPvMYX6U8VwD TNeBxJu5Ex0Izf1NV9CzC3nNaFUYOY8KfN01X5SExAoVTr09ewARAQABzSVLcnp5c3p0b2Yg S296bG93c2tpIDxrcnprQGtlcm5lbC5vcmc+wsGVBBMBCgA/AhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgBYhBJvQfg4MUfjVlne3VBuTQ307QWKbBQJoF1BKBQkWlnSaAAoJEBuTQ307 QWKbHukP/3t4tRp/bvDnxJfmNdNVn0gv9ep3L39IntPalBFwRKytqeQkzAju0whYWg+R/rwp +r2I1Fzwt7+PTjsnMFlh1AZxGDmP5MFkzVsMnfX1lGiXhYSOMP97XL6R1QSXxaWOpGNCDaUl ajorB0lJDcC0q3xAdwzRConxYVhlgmTrRiD8oLlSCD5baEAt5Zw17UTNDnDGmZQKR0fqLpWy 786Lm5OScb7DjEgcA2PRm17st4UQ1kF0rQHokVaotxRM74PPDB8bCsunlghJl1DRK9s1aSuN hL1Pv9VD8b4dFNvCo7b4hfAANPU67W40AaaGZ3UAfmw+1MYyo4QuAZGKzaP2ukbdCD/DYnqi tJy88XqWtyb4UQWKNoQqGKzlYXdKsldYqrLHGoMvj1UN9XcRtXHST/IaLn72o7j7/h/Ac5EL 8lSUVIG4TYn59NyxxAXa07Wi6zjVL1U11fTnFmE29ALYQEXKBI3KUO1A3p4sQWzU7uRmbuxn naUmm8RbpMcOfa9JjlXCLmQ5IP7Rr5tYZUCkZz08LIfF8UMXwH7OOEX87Y++EkAB+pzKZNNd hwoXulTAgjSy+OiaLtuCys9VdXLZ3Zy314azaCU3BoWgaMV0eAW/+gprWMXQM1lrlzvwlD/k whyy9wGf0AEPpLssLVt9VVxNjo6BIkt6d1pMg6mHsUEVzsFNBFVDXDQBEADNkrQYSREUL4D3 Gws46JEoZ9HEQOKtkrwjrzlw/tCmqVzERRPvz2Xg8n7+HRCrgqnodIYoUh5WsU84N03KlLue MNsWLJBvBaubYN4JuJIdRr4dS4oyF1/fQAQPHh8Thpiz0SAZFx6iWKB7Qrz3OrGCjTPcW6ei OMheesVS5hxietSmlin+SilmIAPZHx7n242u6kdHOh+/SyLImKn/dh9RzatVpUKbv34eP1wA GldWsRxbf3WP9pFNObSzI/Bo3kA89Xx2rO2roC+Gq4LeHvo7ptzcLcrqaHUAcZ3CgFG88CnA 6z6lBZn0WyewEcPOPdcUB2Q7D/NiUY+HDiV99rAYPJztjeTrBSTnHeSBPb+qn5ZZGQwIdUW9 YegxWKvXXHTwB5eMzo/RB6vffwqcnHDoe0q7VgzRRZJwpi6aMIXLfeWZ5Wrwaw2zldFuO4Dt 91pFzBSOIpeMtfgb/Pfe/a1WJ/GgaIRIBE+NUqckM+3zJHGmVPqJP/h2Iwv6nw8U+7Yyl6gU BLHFTg2hYnLFJI4Xjg+AX1hHFVKmvl3VBHIsBv0oDcsQWXqY+NaFahT0lRPjYtrTa1v3tem/ JoFzZ4B0p27K+qQCF2R96hVvuEyjzBmdq2esyE6zIqftdo4MOJho8uctOiWbwNNq2U9pPWmu 4vXVFBYIGmpyNPYzRm0QPwARAQABwsF8BBgBCgAmAhsMFiEEm9B+DgxR+NWWd7dUG5NDfTtB YpsFAmgXUF8FCRaWWyoACgkQG5NDfTtBYptO0w//dlXJs5/42hAXKsk+PDg3wyEFb4NpyA1v qmx7SfAzk9Hf6lWwU1O6AbqNMbh6PjEwadKUk1m04S7EjdQLsj/MBSgoQtCT3MDmWUUtHZd5 RYIPnPq3WVB47GtuO6/u375tsxhtf7vt95QSYJwCB+ZUgo4T+FV4hquZ4AsRkbgavtIzQisg Dgv76tnEv3YHV8Jn9mi/Bu0FURF+5kpdMfgo1sq6RXNQ//TVf8yFgRtTUdXxW/qHjlYURrm2 H4kutobVEIxiyu6m05q3e9eZB/TaMMNVORx+1kM3j7f0rwtEYUFzY1ygQfpcMDPl7pRYoJjB dSsm0ZuzDaCwaxg2t8hqQJBzJCezTOIkjHUsWAK+tEbU4Z4SnNpCyM3fBqsgYdJxjyC/tWVT AQ18NRLtPw7tK1rdcwCl0GFQHwSwk5pDpz1NH40e6lU+NcXSeiqkDDRkHlftKPV/dV+lQXiu jWt87ecuHlpL3uuQ0ZZNWqHgZoQLXoqC2ZV5KrtKWb/jyiFX/sxSrodALf0zf+tfHv0FZWT2 zHjUqd0t4njD/UOsuIMOQn4Ig0SdivYPfZukb5cdasKJukG1NOpbW7yRNivaCnfZz6dTawXw XRIV/KDsHQiyVxKvN73bThKhONkcX2LWuD928tAR6XMM2G5ovxLe09vuOzzfTWQDsm++9UKF a/A= In-Reply-To: <20251203-adorable-gila-monster-3d313a-mkl@blackshift.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 03/12/2025 12:20, Marc Kleine-Budde wrote: > On 03.12.2025 11:25:11, Krzysztof Kozlowski wrote: >> On 03/12/2025 11:16, Ahmad Fatoum wrote: >>> Hello Krzysztof, >>> >>> On 11/17/25 5:29 PM, Krzysztof Kozlowski wrote: >>>> On 17/11/2025 17:06, Rob Herring wrote: >>>>>> So you want it to be an ABI for barebox, sure, just make it a binding. >>>>> >>>>> What do you have in mind? Other than standard names for the aliases, >>>>> what can we check here? That a specific alias points to a specific >>>>> path? That would be a bit too much IMO. That would be equivalent to >>>>> specifying possible values in 'reg' for all devices. >>>> >>>> Binding with pattern or list of needed alias names, referenced by given >>>> soc-platform top-level schema. >>>> >>>> One of the points is to make it explicit and obvious (e.g. to Arnd or to >>>> me if I forget, because I follow the same logic of aliases per board) >>>> that these aliases are used outside of kernel. >>>> >>>> Just because ufs/mmc/spi can be used that way, does not mean we should >>>> accept any possible alias into soc.dtsi. >>> >>> I can't see how this could work. A number of boards renumber MMC devices >>> in a different manner than the SoC reference manual: >>> >>> - Changing the alias numbering is an ABI break, because Linux derives >>> its /dev/mmcblkX numbering from it >> >> First, why the alias would change? Isn't the board following the SoC >> numbering in 99.9% cases? >> >> Second, I don't think it is an ABI. We had it ~5 or ~8 years ago where >> the mmcblkX was changing based on probe ordering. Many people setups got >> broken, many people complained and the consensus reply was: please start >> finally using UUID/PARTUIID/LABEL for rootfs. Eventually we got back to >> mmcblkX stability but rule is there - if your cmdline has /dev/mmcblkX, >> then it is your problem. > > In order to use UUID/PARTUIID/LABEL in the kernel command line, the > firmware/bootloader/... has to map from the register value to the > instance to read the UUID/PARTUIID/LABEL from the media. Or have it stored when flashing/configuring the board as part of firmware configuration like U-Boot env. Best regards, Krzysztof