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 F0A5C1FF61D; Fri, 17 Jan 2025 13:36:21 +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=1737120983; cv=none; b=doeXTWt0ge/coM/w14FMg6MsC8D3eN5OBwbRZxEXVcSeHvbdAgt08zfaTUZ7Pnm2acsT9ngi2yg9EKPUIRAtW4cUzxTYBaqLNHEZnYv+g2JGPKbFiY6yRgO6ZmcuG/1LPzQABWg0chmKRjzt1AFx0uAz24wbB6tw993TUI8DXA4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737120983; c=relaxed/simple; bh=mnCt0+GcneoP9kR4t8VIpytKEA0zAIYPNbXWrDKuiyI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aeSQDqKhfYfBKjRTjzr6Emr4kUKz7f96A4e0Ylle/q3Rtnv0h3/o1xhFrc7pN/2kgLLqbVywT7l46uFEe/vUrKOok/GBBFWC5zYZ+JoWbutByRY75UjRE/PRogzpGGejiWRCc6LjN2Kh5ak+S+ARItJiDZbCjdrsfGA7evQACR8= 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=L/ZvofIg; 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="L/ZvofIg" 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=0ksF4VTXO4nIdy/fGUmkRzfewgZbZN5fWTY4cZ+I/Ow=; b=L/ZvofIg7THDmstvI6qKouyAB+ WZW6lWFPkuW7ue8sCEjUBMRgl2Q18OwmNeyUWF7JqMTbULu24Q6E43HmXDtuLO2SzjO7Sbp+eDY9m c1gyT7Q9qPrsPUxdgY0m2xJetorM26QiBVQgasLBiisUILQJNPPOvmj4hKyz0SnZZpiA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1tYmWD-005SM0-A2; Fri, 17 Jan 2025 14:36:13 +0100 Date: Fri, 17 Jan 2025 14:36:13 +0100 From: Andrew Lunn To: Tristram.Ha@microchip.com Cc: maxime.chevallier@bootlin.com, olteanv@gmail.com, Woojung.Huh@microchip.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, UNGLinuxDriver@microchip.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v2] net: dsa: microchip: Add SGMII port support to KSZ9477 switch Message-ID: <91b52099-20de-4b6e-8b05-661e598a3ef3@lunn.ch> References: <20250114024704.36972-1-Tristram.Ha@microchip.com> <20250114160908.les2vsq42ivtrvqe@skbuf> <20250115111042.2bf22b61@fedora.home> 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: > The KSZ9477 SGMII module does use DesignWare IP, but its implementation > is probably too old as some registers do not match. Is there a revision value somewhere in the registers? Maybe the lower nibble of ID registers 2 and 3? > When using XPCS > driver link detection works but the SGMII port does not pass traffic for > some SFPs. It is probably doable to update the XPCS driver to work in > KSZ9477, but there is no way to submit that patch as that may affect > other hardware implementation. We have PHY drivers which change their behaviour based on the revision. So it is possible. And XPCS is used quite a bit, so i don't think it will be an issue finding somebody to do some regression testing. Using a PCS driver is the correct way to go here. So either you need to copy/paste/edit the XPCS driver to create a version specific for you hardware, or you need to extend the XPCS driver so it supports your hardware. Andrew