From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA8FDC05054 for ; Fri, 10 Nov 2023 17:56:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230019AbjKJR4P (ORCPT ); Fri, 10 Nov 2023 12:56:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229982AbjKJRz2 (ORCPT ); Fri, 10 Nov 2023 12:55:28 -0500 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B9772BE05; Fri, 10 Nov 2023 01:18:44 -0800 (PST) Received: by mail.gandi.net (Postfix) with ESMTPSA id BEDE2FF803; Fri, 10 Nov 2023 09:18:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1699607923; 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=JlHs147ceVaFirZwP9qhanL87eStUsCEVWoYX0Pd7Pw=; b=WcN6uEqQTLiAg07Mww8Xh5wguLtukWcC1ATSbprEnegZPropbKOUss8DiJHoGmsJvQBpEI zyoZrTY/WSNPOwcVUyEApnCxqYU3O1WpHqBni9wTioYN8nNwT50hm6ooD0A/P0ZiuSz2zW +tUJlWFOymHBmdii+dH/kzSUpysOob9N6ugznEBd1m/GXe2TXP+QPtwlWWyPJtCrKR+qvL JeMA+j07lGMHEPap/tJo4LYlAt8zDwy/HK7eDPcr6GzATnFKEA5/5BMifUEOclER4I+2YJ iC/sI4oItUB8DxR9KMjus/qAjn/R8eCtHEE0czSfgbXJZB5ZqTBtHmH/rK6jAw== Date: Fri, 10 Nov 2023 10:18:41 +0100 From: Maxime Chevallier To: Jie Luo Cc: , , , , , , , , Subject: Re: [PATCH v2 1/3] net: phy: at803x: add QCA8084 ethernet phy support Message-ID: <20231110101841.27aba547@fedora> In-Reply-To: <0898312d-4796-c142-6401-c9d802d19ff4@quicinc.com> References: <20231108113445.24825-1-quic_luoj@quicinc.com> <20231108113445.24825-2-quic_luoj@quicinc.com> <20231108131250.66d1c236@fedora> <423a3ee3-bed5-02f9-f872-7b5dba64f994@quicinc.com> <20231109101618.009efb45@fedora> <0898312d-4796-c142-6401-c9d802d19ff4@quicinc.com> Organization: Bootlin X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-GND-Sasl: maxime.chevallier@bootlin.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 10 Nov 2023 16:53:39 +0800 Jie Luo wrote: > On 11/9/2023 5:16 PM, Maxime Chevallier wrote: > > Hello, > >=20 > > On Thu, 9 Nov 2023 16:32:36 +0800 > > Jie Luo wrote: > >=20 > > [...] > > =20 > >>> What I understand from this is that this PHY can be used either as a > >>> switch, in which case port 4 would be connected to the host interface > >>> at up to 2.5G, or as a quad-phy, but since it uses QUSGMII the link > >>> speed would be limited to 1G per-port, is that correct ? =20 > >> > >> When the PHY works on the interface mode QUSGMII for quad-phy, all 4 > >> PHYs can support to the max link speed 2.5G, actually the PHY can > >> support to max link speed 2.5G for all supported interface modes > >> including qusgmii and sgmii. =20 > >=20 > > I'm a bit confused then, as the USGMII spec says that Quad USGMII really > > is for quad 10/100/1000 speeds, using 10b/8b encoding. > >=20 > > Aren't you using the USXGMII mode instead, which can convey 4 x 2.5Gbps > > with 66b/64b encoding ? > >=20 > > Thanks, > >=20 > > Maxime =20 >=20 > Hi Maxime, > Yes, for quad PHY mode, it is using 66b/64 encoding. >=20 > it seems that PHY_INTERFACE_MODE_USXGMII is for single port, > so i take the interface name PHY_INTERFACE_MODE_QUSGMII for > quad PHYs here. I see, when I added the QUSGMII mode I wrongly stated that it came from the USXGMII spec where it really comes from USGMII, my bad. > can we apply PHY_INTERFACE_MODE_USXGMII to quad PHYs in this > case(qca8084 quad PHY mode)? =46rom what I can see, the USXGMII mode in the kernel is used as the single-port 10G mode of usxgmii. You might need to create a new mode for quad usxgmii at 10G, the spec calls it 10G-QXGMII I think, but as the spec defines quite a lot of modes, should we define all of them or rely on some other parameters to select the actual mode ? Andrew, Heiner, Russell, what do you think ? Maxime > Thanks, > Jie.