From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (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 70EB22DB7BD for ; Tue, 24 Mar 2026 19:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774380766; cv=none; b=Uppkt8aseiPUMTJvrmXN1gvmqopBCLTQlb1xXhojJPk9gKJ8Tbz4TRzKCJsCwvFiHc+tigogZCt7qP1fqLZXbf3zWCWwoNcx0moIsQLV0vGsj7SNYGgLZi78hmM2ueMRhyY8/S+1xXbsRRVNVZimvOOoHUYJh/A9cpbHgRUjzBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774380766; c=relaxed/simple; bh=w5Gh1aHtMLP0pN4YGj2boonI7PgtCSWo841DqlsRkjY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=be628/REfkv1ViaxWTU3lVcty4ndNmkQw5JpLWGZOyEHXRLhpi097IgiNdx+CSdRVVnr/hRn9QvYWoPbi6O9AwPtvfLHpJfzLOQgzrE5qDF7xqNt02fm7wK9krHCH/O6qp7+Nn+AH0a2GFmY8tV03ZQy9an1di0MU0h/Ea/lEPc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=dcC2m3A9; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="dcC2m3A9" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=akpVw8GG/D7/uN8//pJi89LeOCQWsdhfC6x7h6MTWYI=; b=dcC2m3A96EFNvYQs64zn13BAav ev4U7xNSrJo2A2rwSaV1I7ASWLHM3uCOY6mQVCmQ49t4f9/grks2GAtvy1ySmd/1qKF1Jmq8XwS4w JrXFvqWB8ZL67sNwHhdXiDETDfAlMGrz3RqXox80ycoafzZG4OEy3ONW4zaYKhfOsJvT6dGbET6zO pgF2Q+xyA16NMeqT0VPAsixYdjxYurRKhzG0ly1FL+k1XLyeBess6bS91otPvu3XC4eoioAxCa81w oc9RE/ORwl1ts93aMYMpi5vhC55SzHdZkkalIWz4EN33OowoQglbBpwYYT28ufZzseB8z6HXDVjdw i69GZ9bg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:60794) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w57UX-000000002Y5-1MF1; Tue, 24 Mar 2026 19:32:41 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.98.2) (envelope-from ) id 1w57UV-000000005Jj-2ifC; Tue, 24 Mar 2026 19:32:39 +0000 Date: Tue, 24 Mar 2026 19:32:39 +0000 From: "Russell King (Oracle)" To: Daniel Wagner Cc: netdev@vger.kernel.org, Florian Fainelli , Andrew Lunn , Heiner Kallweit , bcm-kernel-feedback-list@broadcom.com Subject: Re: [PATCH net-next] net: phy: bcm84881: add BCM84891/BCM84892 support Message-ID: References: <20260324152503.1522071-2-wagner.daniel.t@gmail.com> 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-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: Russell King (Oracle) On Tue, Mar 24, 2026 at 06:54:29PM +0000, Daniel Wagner wrote: > Thanks both for the quick review. > > On Tue, Mar 24, 2026 at 3:50 PM Russell King (Oracle) > wrote: > > Is the PHY really using 10GBASE-R or is it using USXGMII. The two are > > different. > [...] > > Is there a code in the 0x4011 register which indicates if it uses > > USXGMII as opposed to 10GBASE-R ? Please clarify. > > It's USXGMII with symbol replication. The MAC receives the negotiated copper > speed, not 10G -- phylink's mac_link_up() is called with the copper speed. > Link works at 100M/1G/2.5G with no rate_matching in the driver, which I think > wouldn't be the case for 10GBASE-R with rate adaptation. One would expect so. > On 0x4011: it reads the same value (0x3107, mode=3) at 1G and at 2.5G copper, > not tracking copper speed. There's no separate USXGMII encoding I can find -- > mode=3 appears to mean "10G SerDes line rate" regardless of protocol, but > admittedly I don't have access to data sheets so this is inference. Looking at the information I have for this register: bit 0 should be link bit (0 = link down, 1 = link up) bits 4:1 indicates the interface and speed over interface: 3 = 10GBASE-R ... 9, 10, 12 and 13 indicate USXGMII at various link speeds. So, as you're seeing 3 for this field, that makes me somewhat suspicious whether this register is implemented the same on these devices. Can you confirm whether bit 0 changes depending whether the PHY has link. I don't know whether that's media link or host-side link, so I suggest checking both. Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!