From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay7-d.mail.gandi.net (relay7-d.mail.gandi.net [217.70.183.200]) (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 951F078F2E; Mon, 24 Feb 2025 09:35:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740389738; cv=none; b=H+D31FrldFAyAb4PtEbEXc8mDZIOfhHhijFNPtdoQGwTwga8oVwmZk+jYzwUDTnYvzdLFNU4XZtgKNzemQW/ILXPt3axcDUvRyh+jgpoqAdi4fwCxF5PMjXOwzj+td16/N/gueWPKuytMM0rZDGKx11zYD9BTRAoOKp7nGTbJB0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740389738; c=relaxed/simple; bh=Lfq2WCwQwVV2cU+ktpJpJCAIJ0AqM3fPlCTamF5mHIM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PYeKdBKC6+W+TJBVr39y26vaqod5HYrRFwcWDUPhMb83u84Q/1XPHDIObR9Zkop2E7ou9yRgET4XhFqQCken5ixp7CpdIvkK/CxA6POa6I9b6p/IR17c4AwhSqC9JxLZO89ZHa7zGUSpYjSXVLu5VpqDlMCY9qwXWkN4LlU6MiM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=NMEWlje+; arc=none smtp.client-ip=217.70.183.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="NMEWlje+" Received: by mail.gandi.net (Postfix) with ESMTPSA id C1DD843209; Mon, 24 Feb 2025 09:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1740389728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pGa772eSKIEFLSlSRxRncn+1VapD5h+fpWIguQax5B0=; b=NMEWlje+MruUWah4Nc7CnSF6Nt3IE69a3glvct/Gr3o32wxgxXI+VHY6zGpICn7Q09iV+w JGZl9w3wWpUkEu8f4anxjpuS6sYs3MIVwc1iHXLDGZvMKENDNfXFyRwgFjbgk/zCeU6i/f rIzFOFIRFw0t4CpmzjoKniE5iEesvBT0NYVJVCLDjEf8eJn05t4mAcwlA/c/wGoUngY17P nEMFVvBUqKQheisDp2x7+uLDBiHtUvJI+XWXw//b4d1cZOWFB/WIRk7trq0bH3+5ZSJ0RC gd8jzMi99EYisT/Qz8SFsPs3MFTgA7qtzfSdygcOGRkC4pHXl0jBWXMYrmEYAA== Date: Mon, 24 Feb 2025 10:35:26 +0100 From: Maxime Chevallier To: "Russell King (Oracle)" Cc: =?UTF-8?B?QmrDuHJu?= Mork , Andrew Lunn , davem@davemloft.net, 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?B?S8O2cnk=?= Maincent , Simon Horman , Romain Gantois , Antoine Tenart , Marek =?UTF-8?B?QmVow7pu?= Subject: Re: [PATCH net-next 0/2] net: phy: sfp: Add single-byte SMBus SFP access Message-ID: <20250224103526.5164e637@fedora> In-Reply-To: References: <20250223172848.1098621-1-maxime.chevallier@bootlin.com> <87r03otsmm.fsf@miraculix.mork.no> <3c6b7b3f-04a2-48ce-b3a9-2ea71041c6d2@lunn.ch> <87ikozu86l.fsf@miraculix.mork.no> Organization: Bootlin X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: netdev@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-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdejkeegvdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkjghfohfogggtgfesthhqredtredtjeenucfhrhhomhepofgrgihimhgvucevhhgvvhgrlhhlihgvrhcuoehmrgigihhmvgdrtghhvghvrghllhhivghrsegsohhothhlihhnrdgtohhmqeenucggtffrrghtthgvrhhnpeeuhfefgffgtdfhgffhvdfhhffhteeutdektefghfetveehheejjefgudeiudehudenucfkphepledtrdekledrudeifedruddvjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeltddrkeelrdduieefrdduvdejpdhhvghlohepfhgvughorhgrpdhmrghilhhfrhhomhepmhgrgihimhgvrdgthhgvvhgrlhhlihgvrhessghoohhtlhhinhdrtghomhdpnhgspghrtghpthhtohepudejpdhrtghpthhtoheplhhinhhugiesrghrmhhlihhnuhigrdhorhhgrdhukhdprhgtphhtthhopegsjhhorhhnsehmohhrkhdrnhhopdhrtghpthhtoheprghnughrvgifsehluhhnnhdrtghhpdhrtghpthhtohepuggrvhgvmhesuggrvhgvmhhlohhfthdrnhgvthdprhgtphhtthhopehkuhgsrgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtohepvgguuhhmrgiivghtsehgo hhoghhlvgdrtghomhdprhgtphhtthhopehprggsvghnihesrhgvughhrghtrdgtohhmpdhrtghpthhtohephhhkrghllhifvghithdusehgmhgrihhlrdgtohhm X-GND-Sasl: maxime.chevallier@bootlin.com On Mon, 24 Feb 2025 08:47:18 +0000 "Russell King (Oracle)" wrote: > On Mon, Feb 24, 2025 at 08:13:22AM +0100, Bj=C3=B8rn Mork wrote: > > Andrew Lunn writes: > > =20 > > >> So, not only do I think that hwmon should be disabled if using SMBus, > > >> but I also think that the kernel should print a warning that SMBus is > > >> being used and therefore e.g. copper modules will be unreliable. We > > >> don't know how the various firmwares in various microprocessors that > > >> convert I2C to MDIO will behave when faced with SMBus transfers. =20 > > > > > > I agree, hwmon should be disabled, and that the kernel should printing > > > a warning that the hardware is broken and that networking is not > > > guaranteed to be reliable. =20 > >=20 > > What do you think will be the effect of such a warning? Who is the > > target audience? > >=20 > > You can obviously add it, and I don't really care. But I believe the > > result will be an endless stream of end users worrying about this scary > > warning and wanting to know what they can do about it. What will be > > your answer? =20 >=20 > ... which is good, because it raises the visibility of crap hardware > and will make people think twice about whether to purchase it, thus > penalising (a little) the sales of badly designed hardware. It's also going to allow users to understand a bit more why all features aren't available. Plugging modules in a true i2c connected cage will report all the features, while plugging on an smbus cage will cause the use of a degraded mode. Not only for hwmon, but as Russell specifies, I doubt all SFP PHY will behave exactly the same... I'll respin without hwmon and with the warning then. Maxime