From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dilbert.mork.no (dilbert.mork.no [65.108.154.246]) (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 18F4D19993B; Tue, 25 Feb 2025 18:08:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=65.108.154.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740506895; cv=none; b=hGhIUgfrSvx9BUfSjZ0gLUhyar2TW/ujcsVZ5ym2c4G2/XOonC/m9fuMIjttIfbq1XrH0eyHFYfWOKl8GhGd4X6sOzlJyZnAWZKaoq6Kx5S0wo9zlTwgqftqVSB8a1HaeOeLqUoFfkVU6PYJqpD04Gzt4D+wJwmOZTWqMGiqYo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740506895; c=relaxed/simple; bh=wefH7Rpmq54N4YPB2U8jXbjMtX7IaHJ1punDFwYSoxE=; h=From:To:Cc:Subject:References:Date:In-Reply-To:Message-ID: MIME-Version:Content-Type; b=MRC2vXpA6DTCc4vKthSoihf1EpwWZNfmcX+aKQD/ijWYnlJksVTzWeIEfq2KMcZjX2X0Yh2QSS3gf10EyRHv99BB5q//amhNsoG60LIXmahUoC4dfiZJwc4JR/eyXhyDsiAv0nj6WuoaVnnejUdQ7vdR43dBWEUTlTFDg9/+UcI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mork.no; spf=pass smtp.mailfrom=miraculix.mork.no; dkim=pass (1024-bit key) header.d=mork.no header.i=@mork.no header.b=oDlD88+F; arc=none smtp.client-ip=65.108.154.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mork.no Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=miraculix.mork.no Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mork.no header.i=@mork.no header.b="oDlD88+F" Authentication-Results: dilbert.mork.no; dkim=pass (1024-bit key; secure) header.d=mork.no header.i=@mork.no header.a=rsa-sha256 header.s=b header.b=oDlD88+F; dkim-atps=neutral Received: from canardo.dyn.mork.no ([IPv6:2a01:799:10de:2e00:0:0:0:1]) (authenticated bits=0) by dilbert.mork.no (8.18.1/8.18.1) with ESMTPSA id 51PI7fID1055590 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=OK); Tue, 25 Feb 2025 18:07:42 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mork.no; s=b; t=1740506861; bh=XJFMpaLBtjREdFMRnck4vJ5NSVGA7jW7HlBTjc+VhXU=; h=From:To:Cc:Subject:References:Date:Message-ID:From; b=oDlD88+FsB93ZAgzk6Lr3ZECuDwCk9p+FZJ+VjSy9NZ3oezLp85OGFJ+7x6+hZcZb bQTk2o0p6lH09pNpwsY1i//T0LsgUb29tFp5zBGds++qh/5PIIOXF7M2sjv+zqi1uN cooA24KToIp6100WGut3zSE6/LU6JzGZUL19Tyvg= Received: from miraculix.mork.no ([IPv6:2a01:799:10de:2e0a:149a:2079:3a3a:3457]) (authenticated bits=0) by canardo.dyn.mork.no (8.18.1/8.18.1) with ESMTPSA id 51PI7fao3242724 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=OK); Tue, 25 Feb 2025 19:07:41 +0100 Received: (nullmailer pid 1167981 invoked by uid 1000); Tue, 25 Feb 2025 18:07:41 -0000 From: =?utf-8?Q?Bj=C3=B8rn_Mork?= To: "Russell King (Oracle)" Cc: Maxime Chevallier , davem@davemloft.net, Andrew Lunn , Jakub Kicinski , Eric Dumazet , Paolo Abeni , Heiner Kallweit , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, Florian Fainelli , =?utf-8?Q?K=C3=B6ry?= Maincent , Simon Horman , Romain Gantois , Antoine Tenart , Marek =?utf-8?Q?Beh=C3=BAn?= Subject: Re: [PATCH net-next 0/2] net: phy: sfp: Add single-byte SMBus SFP access Organization: m References: <20250223172848.1098621-1-maxime.chevallier@bootlin.com> <87o6yqrygp.fsf@miraculix.mork.no> Date: Tue, 25 Feb 2025 19:07:41 +0100 In-Reply-To: (Russell King's message of "Tue, 25 Feb 2025 17:15:36 +0000") Message-ID: <87h64hsxsi.fsf@miraculix.mork.no> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) 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=utf-8 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: clamav-milter 1.0.7 at canardo.mork.no X-Virus-Status: Clean "Russell King (Oracle)" writes: >> I believe you are reading more into the spec than what's actually there. > > So I'm making up the quote above from SFF-8472. Okay, if that's where > this discussion is going, I'm done here. No, not at all. That was not what I meant. Please accept my apologies. This came out wrong. You are absolutely correct about reading the 16bit diagnostic registers you quoted. I would never doubt that. I have an extreme respect for you and your knowledge of these standards and the practical hardware implications. It was the conclusion that this fact prevents SMBus hosts I wanted to question. I still don't see that. Some SMBus hosts might be able do 2 byte reads. And if they can't, then I believe they can safely ignore these registers without being out of spec. Like the proposed solution. I'll shut up now, to avoid confusing the discussion of Maxime's patches further. Bj=C3=B8rn