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 90BA81F30BB; Sat, 28 Mar 2026 03:50:21 +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=1774669821; cv=none; b=orvV8F971lzb/tQ9EAECH6e84Z/J9fy4NBc6iucysYoNRSUr2eyimRPBdokSE4yi3/zFSmh4Th/K0ayYUJH0/e4MDYyYh1RjMMj7mTUirBTA2X/OSCL8pGuQxLNglwAKZ0CrWV42bSj91dTPvZZNnhIqCIAfgAKE9tMkRMsqi5s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774669821; c=relaxed/simple; bh=5k/JPSKn+kKloIgLHKlmvgrCuTizRELOVOkwmdqMLQY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=omjFhyKVm664yC8kr84ZHgNm5GZBJz+EATFilJMb18AmN1hu+88WLSUH3MEzfklxKb2VPGrtBQZpFKUNY61CTeo3BgtQjN9okACeSUFjxu0FAtd+hkjrZ7UpdhYfd/KmDCtxTTrK/RLRVBVFMw+oVWEz6r4eqDXQZYVyZMG9wtE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gisSvAXK; 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="gisSvAXK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 170C6C2BC9E; Sat, 28 Mar 2026 03:50:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774669821; bh=5k/JPSKn+kKloIgLHKlmvgrCuTizRELOVOkwmdqMLQY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gisSvAXKYCRW1xQ3D5XogSDupfdy09Ul3WQHXqbegci7q7DbKruCQ3WNgEpo69WaB CJgxJSA3BC/NH7DdQsaOHVDF+mRLQFRnmwpNMr6N8BAGGovTjSmDutL4IKeDcv2l6d teTTAtWaDDm/irK0aj1HVImEaJEWZBocpbNgx4zNSl/J4VDIwjYp861dj/nGiR/r7c WwjBII6Nbj+vie2bYXDtaiUx9jfGPa8a/x0uN6qPrbBGoTauS9eU/JVumytkPjW4Fb Sx9z7I9g+gdjTahUIjbR4bO2ubGyD+NnGdLq+PlcsCfVd12Eeds8tI0TjQIur6XcHI p7qB7PMk6xmbg== Date: Fri, 27 Mar 2026 20:50:20 -0700 From: Jakub Kicinski To: Jan Hoffmann Cc: Russell King , Andrew Lunn , Heiner Kallweit , "David S. Miller" , Eric Dumazet , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next] net: sfp: add quirk for ZOERAX SFP-2.5G-T Message-ID: <20260327205020.1c020731@kernel.org> In-Reply-To: <20260325164034.1542787-1-jan@3e8.eu> References: <20260325164034.1542787-1-jan@3e8.eu> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 25 Mar 2026 17:35:58 +0100 Jan Hoffmann wrote: > This is a 2.5G copper module which appears to be based on a Motorcomm > YT8821 PHY. There doesn't seem to be a usable way to to access the PHY > (I2C address 0x56 provides only read-only C22 access, and Rollball is > also not working). > > The module does not report the correct extended compliance code for > 2.5GBase-T, and instead claims to support SONET OC-48 and Fibre Channel: > > Identifier : 0x03 (SFP) > Extended identifier : 0x04 (GBIC/SFP defined by 2-wire interface ID) > Connector : 0x07 (LC) > Transceiver codes : 0x00 0x01 0x00 0x00 0x40 0x40 0x04 0x00 0x00 > Transceiver type : FC: Multimode, 50um (M5) > Encoding : 0x05 (SONET Scrambled) > BR Nominal : 2500MBd > > Despite this, the kernel still sets 2500Base-X as interface mode based > on the (incorrect) nominal signaling rate. > > However, it is also necessary to disable auto-negotiation for the module > to actually work. Thus, create a SFP quirk to do this. > > Signed-off-by: Jan Hoffmann > --- > Note: I'm not quite sure "sfp_quirk_disable_autoneg" is enough here, or > if it would be appropriate to use the full "sfp_quirk_oem_2_5g" quirk > due to the not really correct compliance code / nominal signaling rate. I'm no SFP expert but just going by the naming I strongly suspect that the module is the same hardware as "SFP-2.5G-T" from "FS", so keeping quirks consistent makes sense?