From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) (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 090121DFE8; Mon, 19 Feb 2024 14:31:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708353076; cv=none; b=tbQQDAvZ/fUmFIU2xrOVxxll6M2zabcs/jOeJ/JcU5SxpExFgYdURmpAPZ2qkWBM07gIKYz5gKfEDSVE4E7LbYwalxY9ijEEFRc2VYAaHjTIi2rcfgJ/Bjbt4NPWHnXgkVhxKP+4uH/RMxFvZ2y6PPInr7H84NkJ6dg41yGznII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708353076; c=relaxed/simple; bh=kCExhr7TI0B5O0k5tOI7V68szWpBz5xEoI5w1iUnUEw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JBeWwuyMX1gUxDV5jgs3x3jUSUCgxCf+Px3+uiUbph0SeHtR7JeB/2vcxagua89/CbJ8LzLt9lOTBJdM6n5t4QUVRpwlGwNDl8EtxPxbMY0HwYXod1qfiFHxk8GMFlDNbI1NriDt+vHbP2x+69lbb4mVTFAsscjIFOIhO3kYB7E= 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=U/s9u0OS; arc=none smtp.client-ip=217.70.183.201 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="U/s9u0OS" Received: by mail.gandi.net (Postfix) with ESMTPSA id 2E40C1BF206; Mon, 19 Feb 2024 14:31:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1708353072; 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=9h+OMrQCyhqHA7MCzpM0VlZZ6CwDDvEtHV/K94gz0WI=; b=U/s9u0OSp/Z7R2FUlgP0FV/wusIZrolBvVwUWtIO4FxFiOGCiQTMv/8XnFtg5S6NqyIWls zwzzQt1XSmq6BRxzXIZWCrE1Mn+nR6GJE1CpM4Mfjbsrwlq300d3xNFDglvo2dif8rchV+ bE75OAq8FhfduMysPMIFJJ77YSaynAKfxd30GD+0b1cOrBQB86OKMpZWQHr476u4qsYGlJ ovL1G1kBYbNNJ1RkO0CvO2wOA5A1TXYCrqfB7sVXJbIaECwhCshHM8fD7VprqiA6yqQD3U zfE7HMT1o0+nr1XRTfOqoHSTV535PlLcOm6JIluUhlpI+4bFOxV+0O0VJ9/3QA== Date: Mon, 19 Feb 2024 15:31:06 +0100 From: =?UTF-8?B?S8O2cnk=?= Maincent To: Oleksij Rempel Cc: Andrew Lunn , Rob Herring , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jonathan Corbet , Luis Chamberlain , Russ Weight , Greg Kroah-Hartman , "Rafael J. Wysocki" , Krzysztof Kozlowski , Conor Dooley , Mark Brown , Frank Rowand , Heiner Kallweit , Russell King , Thomas Petazzoni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, devicetree@vger.kernel.org, Dent Project Subject: Re: [PATCH net-next v3 14/17] dt-bindings: net: pse-pd: Add bindings for PD692x0 PSE controller Message-ID: <20240219153106.19e83213@kmaincent-XPS-13-7390> In-Reply-To: References: <20240208-feature_poe-v3-0-531d2674469e@bootlin.com> <20240208-feature_poe-v3-14-531d2674469e@bootlin.com> <20240209145727.GA3702230-robh@kernel.org> <618be4b1-c52c-4b8f-8818-1e4150867cad@lunn.ch> <65099b67-b7dc-4d78-ba42-d550aae2c31e@lunn.ch> Organization: bootlin X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-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-Sasl: kory.maincent@bootlin.com On Fri, 16 Feb 2024 08:47:14 +0100 Oleksij Rempel wrote: > > > > So, either somebody needs to understand 1000BaseT and can say the > > proposed binding works, or we explicitly document the binding is > > limited to 10BaseT and 100BaseT. =20 >=20 > I asked the internet and found the answer: Some PSE/PD implementations > are not compatible with 1000BaseT. >=20 > See Figure 33=E2=80=934=E2=80=9410BASE-T/100BASE-TX Endpoint PSE location= overview. > Alternative B show a variant where power is injected directly to pairs > without using magnetics as it is done for Alternative A (phantom > delivery - over magnetics). >=20 > So, we have following variants of 2 pairs PoE: > +---------+---------------+-------------------+---------------------+----= ----------------+ > | Variant | Alternative | Polarity | Power Feeding Type | > Compatibility with | | | (a/b) | (Direct/Reverse) | > (Direct/Phantom) | 1000BaseT | > +=3D=3D=3D=3D=3D=3D=3D=3D=3D+=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D+=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D+=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D+=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D+ > | 1 | a | Direct | Phantom | Yes > | > +---------+---------------+-------------------+---------------------+----= ----------------+ > | 2 | a | Reverse | Phantom | Yes > | > +---------+---------------+-------------------+---------------------+----= ----------------+ > | 3 | b | Direct | Phantom | Yes > | > +---------+---------------+-------------------+---------------------+----= ----------------+ > | 4 | b | Reverse | Phantom | Yes > | > +---------+---------------+-------------------+---------------------+----= ----------------+ > | 5 | b | Direct | Direct | No > | > +---------+---------------+-------------------+---------------------+----= ----------------+ > | 6 | b | Reverse | Direct | No > | > +---------+---------------+-------------------+---------------------+----= ----------------+ Maybe we could remove the polarity column on this table as it does not bring more information. It is also already explained on the PI pinout alternatives table. Also we should document that a 4pairs PSE supporting only 10/100BaseT (which mean no magnetics on pinout AlternativeB) may not be compatible with a 4pai= rs 1GBaseT PD. > For this case, it will be good if systems knows supported modes, so user > can get this information directly. For example with ethtool Yes. Regards, --=20 K=C3=B6ry Maincent, Bootlin Embedded Linux and kernel engineering https://bootlin.com