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 0442F2F5316; Thu, 13 Nov 2025 16:46:53 +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=1763052414; cv=none; b=BJoh0/cwox+B4C3XST6RpMd5e1BlPaR3Xh48yNFRGlPVdHCq2InEnzyLKO0SwLi20M7xZ668t4Y28GfAbQdWKmGeyS0gWqnTmOodYU7ajU+dBTpaQIdMGZjRzPhSaywMhURirXuyOsJnHdUckm9scb6PSEvFdICPVxSbQc85eHo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052414; c=relaxed/simple; bh=6iUKG8NMVDDWdZqxXodaG87MpkmvyRMnCj8mZaI9oGw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jjsS9wQr4h9zPexPpWhgr9ekF/N7PbXQlc45gAZRUaTx2csEXr9QOaTE2WH9osh+8GnljaEJbdv/6Znoa8IXZxsrORcqSC7qXFaOEETTr2jnUml1z5ZX5Q7BzB9EiMRbYonyrFDxeYOjGxgaNDCB1G3wWsw/ZyOpfEOgHfKCISo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WQpzzHWZ; 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="WQpzzHWZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E84FC4CEF1; Thu, 13 Nov 2025 16:46:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763052413; bh=6iUKG8NMVDDWdZqxXodaG87MpkmvyRMnCj8mZaI9oGw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WQpzzHWZfMEVz7RF4t4SEwrbP4KnU0Mrr9M8bfDObp4UMhIvCk0AlwJpTVufHaRaf HaFOR3enGDvFET1hyxQjgRoVgPm+fdkx+iwYVNYNTX3nmmT/kln7mrJYCYqO7tkEUu reTVMej3LCfiM5gsJy+BqqMDUPTdNKHjy6UPtknxZ0YS6wyOywEWML4WUUr+aKd/uX ORtQUsIR5Igrh+FzXxW1r/PqEoVa4Uz5eNzNisf1TYPM3SRbNdPCoFdAH6Wbr4T1Pl I6OK88FQACAHQjzNTR+bKj7ksLuRnhM81EOQzPYAjDxbInFxaFqW7qph15laI/tp1e 1Tw/WNah60/5A== Date: Thu, 13 Nov 2025 22:16:49 +0530 From: Vinod Koul To: Vladimir Oltean Cc: linux-phy@lists.infradead.org, Ioana Ciornei , Kishon Vijay Abraham I , Josua Mayer , linux-kernel@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v4 phy 01/16] dt-bindings: phy: lynx-28g: permit lane OF PHY providers Message-ID: References: <20251110092241.1306838-1-vladimir.oltean@nxp.com> <20251110092241.1306838-2-vladimir.oltean@nxp.com> Precedence: bulk X-Mailing-List: devicetree@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: <20251110092241.1306838-2-vladimir.oltean@nxp.com> On 10-11-25, 11:22, Vladimir Oltean wrote: > Josua Mayer requested to have OF nodes for each lane, so that he > (and other board developers) can further describe electrical parameters > individually. > > For this use case, we need a container node to apply the already > existing Documentation/devicetree/bindings/phy/transmit-amplitude.yaml, > plus whatever other schemas might get standardized for TX equalization > parameters, polarity inversion etc. > > When lane OF nodes exist, these are also PHY providers ("phys" phandles > can point directly to them). Compare that to the existing binding, where > the PHY provider is the top-level SerDes node, and the second cell in > the "phys" phandle specifies the lane index. > > The new binding format overlaps over the old one without interfering, > but there is a caveat: > > Existing device trees, which already have "phys = <&serdes1 0>" cannot > be converted to "phys = <&serdes_1_lane_a>", because in doing so, we > would break compatibility with old kernels which don't understand how to > translate the latter phandle to a PHY. > > The transition to the new phandle format can be performed only after a > reasonable amount of time has elapsed after this schema change and the > corresponding driver change have been backported to stable kernels. > > However, the aforementioned transition is not strictly necessary, and > the "hybrid" description (where individual lanes have their own OF node, > but are not pointed to by the "phys" phandle) can remain for an > indefinite amount of time, even if a little inelegant. > > For newly introduced device trees, where there are no compatibility > concerns with old kernels to speak of, it is strongly recommended to use > the "phys = <&serdes_1_lane_a>" format. The same holds for phandles > towards lanes of LX2160A SerDes #3, which at the time of writing is not > yet described in fsl-lx2160a.dtsi, so there is no legacy to maintain. > > To avoid the strange situation where we have a "phy" (SerDes node) -> > "phy" (lane node) hierarchy, let's rename the expected name of the > top-level node to "serdes", and update the example too. This has a > theoretical chance of causing regressions if bootloaders search for > hardcoded paths rather than using aliases, but to the best of my > knowledge, for LX2160A/LX2162A this is not the case. > > Link: https://lore.kernel.org/lkml/02270f62-9334-400c-b7b9-7e6a44dbbfc9@solid-run.com/ > Cc: Rob Herring > Cc: Krzysztof Kozlowski > Cc: Conor Dooley > Cc: devicetree@vger.kernel.org > Cc: stable@vger.kernel.org You can keep cc lines after s-o-b line after the '---' separator, that way it will be skipped when applying while email client will cc folks. My main question was cc stable, for a binding additions, that might not be helpful as dts may not have these updates, so why port bindings? -- ~Vinod