From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 A5DE51B0F09; Tue, 3 Dec 2024 20:26:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733257599; cv=none; b=SgqDhHdBwbdYOSIUTQC4CH60QgDzDzc6rdZy2Y5Vsq7qbc8Iw2DC7/0eAi0jWH10Q0B+mkTaDvhXetH1t9M1B45JNg0zPv2R/PhDp2TdQSxbdqYZAAw+I+mjukhTWqM8AP6abWtkbwW03lqXGmQtRvoG3wD1HBVC2hKTp2YSRjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733257599; c=relaxed/simple; bh=62FGdj89Sxt78umBMCRkvM4YUdCIKpA2B9i67nQQzWU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nbISajfycBQfo74KAc84xeDKg63Vlq6y18+VoC6gZ8+MVnnzFwbnmdxgvYK8k/xCONa+NHtchah6mm79oo0nCKBeqcrt4bXEVpK0Wp5VLgLcapwp9WXIejBtJO9Nm0YauSe9b7hbjShr1r7TmViMd9LA/qYHVkzoB+2ECTfM6Os= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=ljXk21QP; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="ljXk21QP" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=MgboeHSqQp6/IluBIsDw2q9e1F3qAshf0GDnZunVBts=; b=ljXk21QPRZAWDZ6BR0OWMC3cnu IWCkt1lKE5fU+1qKsl+niqDtHBp28kCbK0ZTurlPkAGVnMZvvjyLYW9bJaf9+TbmpOROQT0aJcRCE SbSJGHsjF2j33+jG8W73rgNgytSxmoHJEnR4ETpEq4n+s0QnCoRmjYxZNUkn6hN/GvXw=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1tIZTb-00F81g-9M; Tue, 03 Dec 2024 21:26:31 +0100 Date: Tue, 3 Dec 2024 21:26:31 +0100 From: Andrew Lunn To: Oleksij Rempel Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Woojung Huh , Andrew Lunn , kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, UNGLinuxDriver@microchip.com, Phil Elwell Subject: Re: [PATCH net-next v1 01/21] net: usb: lan78xx: Remove LAN8835 PHY fixup Message-ID: References: <20241203072154.2440034-1-o.rempel@pengutronix.de> <20241203072154.2440034-2-o.rempel@pengutronix.de> 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=us-ascii Content-Disposition: inline In-Reply-To: <20241203072154.2440034-2-o.rempel@pengutronix.de> On Tue, Dec 03, 2024 at 08:21:34AM +0100, Oleksij Rempel wrote: > Remove the PHY fixup for the LAN8835 PHY in the lan78xx driver due to > the following reasons: > > - There is no publicly available information about the LAN8835 PHY. > However, it appears to be the integrated PHY used in the LAN7800 and > LAN7850 USB Ethernet controllers. These PHYs use the GMII interface, > not RGMII as configured by the fixup. > > - The correct driver for handling the LAN8835 PHY functionality is the > Microchip PHY driver (`drivers/net/phy/microchip.c`), which properly > supports these integrated PHYs. > > - The PHY ID `0x0007C130` is actually used by the LAN8742A PHY, which > only supports RMII. This interface is incompatible with the LAN78xx > MAC, as the LAN7801 (the only LAN78xx version without an integrated > PHY) supports only RGMII. > > - The mask applied for this fixup is overly broad, inadvertently > covering both Microchip LAN88xx PHYs and unrelated SMSC LAN8742A PHYs, > leading to potential conflicts with other devices. > > - Testing has shown that removing this fixup for LAN7800 and LAN7850 > does not result in any noticeable difference in functionality, as the > Microchip PHY driver (`drivers/net/phy/microchip.c`) handles all > necessary configurations for these integrated PHYs. > > - Registering this fixup globally (not limited to USB devices) risks > conflicts by unintentionally modifying other interfaces whenever a > LAN7801 adapter is connected to the system. > > Note that both LAN7800 and LAN7850 USB Ethernet controllers use an > integrated PHY with the ID `0x0007C132`. Additionally, the LAN7515, a > specialized part for Raspberry Pi, includes an integrated LAN7800 USB > Ethernet controller and USB hub in a multifunctional chip design, and it > also uses the same PHY ID (`0x0007C132`). I had a long frustrating discussion about adding yet more such fixups a while ago with somebody how did not understand the implications of adding another one. It is good to see this one being removed, with a good explanation why. Reviewed-by: Andrew Lunn Andrew