From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9BBA91CB326; Tue, 1 Oct 2024 14:13:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.194.8.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727791987; cv=none; b=SiCD1WgpePmg74NwU4wUq7yotlYA0c07Saaa7YA6tsiPlKiJKsHsRSGzsNfVaAfTipHigUfkD+OBEiegD9Yn23d+4QRsCrTBMcXZoC5pC9fobGduOnW8nsMh//ldnlnPeTtD2+t7nm4zkXyxvvrMssUxYsflVFdEqQ/gXJ/l5vk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727791987; c=relaxed/simple; bh=Bv1lZ9pYZX4a1F0IxYaJoGt/bx5QFgBAtiX+7uCGqXc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aEHDnJaX+jX6oFf6X9/evRXnJ9/1T5oE3qkUCTrWOFWd2bFzJZRShl+6gqgUjWVNzDCB/p8xRC5SVAlWR9vno9gt5oMO1Nu17LprdDXE90+1EmLlhIPqUsQJxzt0mwzExIGxePeCCddsZsR5BGvmxd7FwUdxNFSCRazcpugWqWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it; spf=pass smtp.mailfrom=dolcini.it; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b=spjDrQm6; arc=none smtp.client-ip=217.194.8.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dolcini.it Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b="spjDrQm6" Received: from gaggiata.pivistrello.it (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 780F01F9BE; Tue, 1 Oct 2024 16:13:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1727791981; bh=HkIi6vdWzZRL9mRqwCQESkyqXZUUQQRvVyjVDYHczpM=; h=Received:From:To:Subject; b=spjDrQm6RjfD+ES2VkYGpNMvdca/QmvzvP6MXC0fmwGxrAbgSdz7UwYAmX6PFx7zI uwxc4Fn6lACjXQyDQNFDZ0Umt4t2ntYnTiXSN4hRiD8+bRTpDQuBmwDjRqVFOU53zY 36NNeUAVjrtPfve5B9OZt0bJr7ctLH465/OyEWTpRhyjPllzC3gT/FtlkZpN/aikkx 4FWoVuZ7a3rtzbrBl/7j86JepQDqqFCp1neXYIGPKOayaKUiKNQLArTCmjmfjfw3kj VTsuL1y58XI26bRfZKKa8mZbcYN3HpISD93SZrx4JSVnHU3ujGO8xIiE6d9mi5gbkt r76CSW6vPcPXA== Received: by gaggiata.pivistrello.it (Postfix, from userid 1000) id 15CCF7F919; Tue, 1 Oct 2024 16:13:01 +0200 (CEST) Date: Tue, 1 Oct 2024 16:13:01 +0200 From: Francesco Dolcini To: Krzysztof Kozlowski Cc: Francesco Dolcini , Nishanth Menon , =?iso-8859-1?Q?Jo=E3o_Paulo_Gon=E7alves?= , Vignesh Raghavendra , Tero Kristo , Rob Herring , Krzysztof Kozlowski , Conor Dooley , =?iso-8859-1?Q?Jo=E3o_Paulo_Gon=E7alves?= , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] arm64: dts: ti: k3-am62-verdin: Update tla2024 adc compatible Message-ID: References: <20241001111413.10390-1-jpaulo.silvagoncalves@gmail.com> <20241001130128.GA36341@francesco-nb> <3d9de1b8-488b-4df5-b984-7581b1d02241@kernel.org> 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3d9de1b8-488b-4df5-b984-7581b1d02241@kernel.org> On Tue, Oct 01, 2024 at 03:59:39PM +0200, Krzysztof Kozlowski wrote: > On 01/10/2024 15:01, Francesco Dolcini wrote: > > On Tue, Oct 01, 2024 at 01:54:56PM +0200, Krzysztof Kozlowski wrote: > >> On 01/10/2024 13:14, João Paulo Gonçalves wrote: > >>> From: João Paulo Gonçalves > >>> > >>> With commit f1c9ce0ced2d ("iio: adc: ti-ads1015: Add TLA2024 support") a > >>> new compatible was introduced for TLA2024 ADC. Update the device > >>> tree to use the correct compatible for the Verdin-AM62 hardware. > >>> > >>> Signed-off-by: João Paulo Gonçalves > >>> --- > >>> arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi > >>> index 5bef31b8577b..f201722d81b3 100644 > >>> --- a/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi > >>> +++ b/arch/arm64/boot/dts/ti/k3-am62-verdin.dtsi > >>> @@ -1220,7 +1220,7 @@ sensor@48 { > >>> }; > >>> > >>> adc@49 { > >>> - compatible = "ti,ads1015"; > >>> + compatible = "ti,tla2024"; > >> > >> So it is not always TI, who breaks their users. :) (as pointed out in > >> LPC DT BoF). > > > > So, let's adjust what I said at that time, I think is important, and I > > appreciate you giving me an excuse for doing that :-) > > > > Lately as Toradex we are working a lot with TI, and one of the reasons is > > that they have a great software support, backed-up by a great strategy > > on the way they contribute to the various upstream projects they build > > their SDK on top (Linux, U-Boot, and more). > > > > With that is normal that while working so closely with them we find > > issues, everybody have those, it's just that those are the one we > > care the most at the moment :-). Not to mention that we started working > > with TI a couple of years ago, so TI is still somehow "new" to us and we > > are still "learning". > > > > On this regards I was recently working on updating our BSP to the > > latest SDK from TI, that is based on a v6.6 stable kernel and looking at > > the patches we had to apply on top, the total counts of the patches we > > do not have in mainline to support the board subject of this patch is > > just _zero_. This to me is a great achievement. > > > > Nishant: this is also for you, and feel free to "market" this > > internally/externally :-) > > > > > >> If you want to break users, sure, but at least explain in commit msg why. > > > > Now, on this specific topic, the actual device that is assembled on this > > board is a TI TLA2024, and it's like that since ever, the board never > > changed. The current compatible is not matching what is assembled on > > board. It works because the device is close enough to TI ADS1015. > > > > With that said, I do not think this is breaking any actual compatibility > > issue. > > > > - The old DTB will keep working with old and new kernel. > > New DTB stops working with old kernel and this is what we talked about > during LPC. My mind at that time was really on using old DTB with a new kernel, not that other way around. In any case, I do not think that this comment applies on this specific case, as I wrote you cannot really run this board on a kernel that does not support the ti,tla2024 compatible. > All out-of-tree users of this DTS, like other operating systems, will be > affected as well probably. Well, yes. From what I know those user do not exist and this is just theoretical, but, I might be as well wrong and I see your point. So, let me try to sum it up, I see 2 options: 1 - we drop this change. this is fine for me. 2 - we add a comment in the commit message that this is a breaking change, and while I am not aware of any impact with real software that is available today, I might have incomplete information. Francesco