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 07CCEC4332F for ; Thu, 9 Nov 2023 09:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234268AbjKIJQ0 (ORCPT ); Thu, 9 Nov 2023 04:16:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233778AbjKIJQY (ORCPT ); Thu, 9 Nov 2023 04:16:24 -0500 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::223]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B745A268D; Thu, 9 Nov 2023 01:16:21 -0800 (PST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 5B80460009; Thu, 9 Nov 2023 09:16:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1699521380; 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=G3yh8PqTdV++lp9Hlak0Ojq8NdsXQDIGt0OtBSub/wI=; b=bk/jsVoPypHHxC762ajM6+kby/KFGKqJPJCv+Zh6Alhuvow3sYqqCnsqeNm+PR/poNdoIs FeplkxDXwNN6TBKqr2X2Jw7eKESVdroWDH/kw059/rSzHZvZcof50gyCsHih4H33DwZNNG ji+AVRBQTBELapFe4/QfUBjLyntZybveTS9Qj3+cQxOkf5MT2Vk+dYkOqkGJXKwNFII4LU FPjvO8Y0y0CgarKViiKki8CgWm/Cxc2dxVevPFfNUjLOBHF0uTHRa21oK6OqPoeZ4FQwmd 3Cmybvpdr4gMqwtJIujNGE9qrNcBgkNRhAt6uM/A9SykbDZgDZK9xHCC2o4rYQ== Date: Thu, 9 Nov 2023 10:16:18 +0100 From: Maxime Chevallier To: Jie Luo Cc: , , , , , , , , Subject: Re: [PATCH v2 1/3] net: phy: at803x: add QCA8084 ethernet phy support Message-ID: <20231109101618.009efb45@fedora> In-Reply-To: <423a3ee3-bed5-02f9-f872-7b5dba64f994@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> 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: 7bit X-GND-Sasl: maxime.chevallier@bootlin.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Thu, 9 Nov 2023 16:32:36 +0800 Jie Luo wrote: [...] > > 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 ? > > 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. 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. Aren't you using the USXGMII mode instead, which can convey 4 x 2.5Gbps with 66b/64b encoding ? Thanks, Maxime