From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 15D534431 for ; Mon, 5 Jun 2023 10:45:16 +0000 (UTC) Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82AF0FA for ; Mon, 5 Jun 2023 03:45:15 -0700 (PDT) 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-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding: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=j/ORUKfLFYNZMSfZmNpxZapN6ulrZ1+RHN+E+Me8a8k=; b=iJXCLsSYAj+n6o5g8nK5YmrUAY dre5z++g8ndEJFknXddosQ+B/EITiv7suteaecLFz7uF17z8QYtcLDNgUGX9sPthD1HtCSeyOiB0i GGm1YGfX0PLpDKTXyvLE8XKR57UFLAuL3TgFUCA3XLWWoXXTPxZP9yj6FuOCoA/teumPKElJlY5Gi xB3QA4xKV3yDMAgGJK6SNLqR2e8pd4z4354r1RlMxHbD1YT2pfvfWAS9m75sY9007gGo8duzIfAh1 sEPBFiaCbvhsOkua/f6BZDTW0B98Qj1vYWLLKQBFcTObMqfDnvz5Y2mxyH3GBKMi+2bOzvYFZeJXv 9hcpdf/g==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:36702) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1q67i5-0003pP-Lv; Mon, 05 Jun 2023 11:45:13 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1q67i4-00062Q-SW; Mon, 05 Jun 2023 11:45:12 +0100 Date: Mon, 5 Jun 2023 11:45:12 +0100 From: "Russell King (Oracle)" To: Maxime Chevallier Cc: Andrew Lunn , netdev@vger.kernel.org Subject: Re: QUSGMII control word Message-ID: References: <20230605081334.3258befa@pc-7.home> Precedence: bulk X-Mailing-List: netdev@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: <20230605081334.3258befa@pc-7.home> Sender: Russell King (Oracle) X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Mon, Jun 05, 2023 at 08:13:34AM +0200, Maxime Chevallier wrote: > Hello Russell, > > On Fri, 2 Jun 2023 13:18:03 +0100 > "Russell King (Oracle)" wrote: > > > Hi Maxime, > > > > Looking at your commit which introduced QUSGMII - > > 5e61fe157a27 ("net: phy: Introduce QUSGMII PHY mode"), are you sure > > your decoding of the control word is correct? > > > > I've found some information online which suggests that QUSGMII uses a > > slightly different format to the control word from SGMII. Most of the > > bits are the same, but the speed bits occupy the three bits from 11:9, > > and 10M, 100M and 1G are encoded using bits 10:9, whereas in SGMII > > they are bits 11:10. In other words, in QUSGMII they are shifted one > > bit down. In your commit, you used the SGMII decoder for QUSGMII, > > which would mean we'd be picking out the wrong bits for decoding the > > speed. > > > > QUSGMII also introduces EEE information into bits 8 and 7 whereas > > these are reserved in SGMII. > > > > Please could you take a look, because I think we need a different > > decoder for the QUSGMII speed bits. > > I've taken a look at it, back when I sent that patch I didn't have > access to the full documentation and used a vendor reference > implementation as a basis... I managed to get my hands on the proper > doc and the control word being used looks to be the usxgmii control > word, which matches with the offset you are seeing. > > Do you have a patch or should I send a followup ? I don't have a patch. > Out of curiosity, on which hardware did you find this ? No, it's something I noticed when reviewing some documentation I have. > I still have some patches of PCH extensions around, but didn't get any > room in my schedule to move forward with it. Is it something that you > plan on using ? No plans, sorry! :D -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!