From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 8AD1E33FE33; Thu, 3 Sep 2026 08:59:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788425984; cv=none; b=l+C28Pk9d4IcUia5t0q8xS0tib9Kq5uoAN9sZKshIcc1T0yf6G6PQ80X4973hpO2LQvOFmgTdJO+MYKVhtEjgX+TgcvkAhmc/4eEyhy6hpUITSsUzT0UbkxrbkUDpQEMkq0oLg7mKqlEti2D0Wk73aiQKrnUu9EQxKUAlQrueEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788425984; c=relaxed/simple; bh=kVnEmuck5YlW+cysPHQ3yekEWh5fBAZYSZ+FOgY3PiI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JFJkUNei/2tZYwTUZEYJQW1dzIq7WyEO6OtwtdKLt/zGjmdbo/G8gy1Awds+XlzTkQ1qHF7YT32S0JZ1z4r7wrQO6rCoRS23rmc6epqOTgab6C0yaTIvw4ntplROXYbo/ZIa9kfj8X1u78P2Rnnf5hzvoPCI/0/Qxu9NravS4CM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=NSAfZPyF; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="NSAfZPyF" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id E7D5D4E414EA; Thu, 3 Sep 2026 08:59:40 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id B3073602B8; Thu, 3 Sep 2026 08:59:40 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 9D55D11C79B6F; Thu, 3 Sep 2026 10:59:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1788425975; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:content-language:in-reply-to:references; bh=PiL0n2uXooBtcEc368JZodVn4EdHp6AGVsRm0KQPqdM=; b=NSAfZPyFa9kKtVaFiAwBkbsvfBe6WXTmXNm2f7foXwBePTVa3H+um9g9CFDz2W8fd/X5xc E8nIZDWfVUXYxXhzu0UxH8/n+TJc2bvmjpDPFp0h2uWAimVXBXZFXIJfDnlpbC/BICsVHO 7OgGrMYElME/1bbRs1vfRILU5p97XBKrDBpkYQHx0vntvAqBPNmT/95Rfcn6qO2umjS/dz 6bNKILtLX1sD6vMvjgaFXhbdCNFXR3o05SWWTOZ3FmVvXWWFNSL6JpLYpfHaj/zqjTK7JA 1+EbewU6Kz/XhoqxrQ9mynIRFw4QwXYbxT9kLtPnVi4X1WF8Vvs2BzeoooPLaQ== Message-ID: <54544759-8668-41af-ba05-68b8b3f00416@bootlin.com> Date: Thu, 3 Sep 2026 10:59:30 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v3 08/10] net: stmmac: dwmac-rk: add SGMII support for RK3568 To: Coia Prant , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Vinod Koul , Maxime Coquelin , Alexandre Torgue , Lad Prabhakar , Romain Gantois , Heiner Kallweit Cc: Neil Armstrong , Russell King , Shawn Lin , David Heidelberg , netdev@vger.kernel.org, linux-rockchip@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, linux-renesas-soc@vger.kernel.org References: <20260901150111.141037-1-coiaprant@gmail.com> <20260901150111.141037-9-coiaprant@gmail.com> Content-Language: en-US From: Maxime Chevallier In-Reply-To: <20260901150111.141037-9-coiaprant@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 Hi On 9/1/26 17:01, Coia Prant wrote: > The RK3568 SoC integrates a Synopsys DesignWare XPCS that can be > connected to GMAC0 or GMAC1 in SGMII mode. Add the necessary glue > logic to support this configuration. > > The current dwmac-rk driver does not support SGMII mode. SGMII > requires a PCS to handle auto-negotiation and link state reporting, > but the existing driver only supports RGMII and RMII. > > Add a set_to_sgmii() callback to configure the GMAC GRF register for > SGMII mode (bit 7 set, interface selection bits 4:6 cleared). Also > add a supports_sgmii flag to indicate SGMII capability. > > Provide pcs_init/pcs_exit callbacks to create/destroy the XPCS via > xpcs_rk_create() from the Rockchip XPCS platform driver, and a > select_pcs callback to return the XPCS to phylink. > > While at it, fix the clock enable ordering in rk_gmac_powerup(): > gmac_clk_enable() is now called before any register access, including > the SGMII mode setup path. Previously SGMII mode would bypass the > clock enable via a goto, which could cause synchronous external abort > when accessing MAC registers with the clock domain disabled. > > Also clean up the error handling in rk_gmac_powerup() by using a > unified clk_disable label, and add error handling for the default > (unhandled interface) case. > > SGMII In-band vs Out-of-band > ============================ > On RK3568, the MAC clock is fixed at 125 MHz and cannot be dynamically > changed by the stmmac core's set_clk_tx_rate callback. In-band mode > works because the PCS handles rate adaptation internally. Out-of-band > mode does not work because the MAC would need to change the clock rate > to 125/12.5/1.25 MHz for 1000/100/10 Mbps respectively, and the clock > is fixed. > > Enable default_an_inband for SGMII and disable the generic stmmac > set_clk_tx_rate callback. This forces phylink to use in-band mode, > where the PCS is responsible for speed/duplex negotiation. Without > this, the stmmac core would attempt to change the clock rate on speed > changes, causing TX to work but RX to fail. > > Link: https://dl.radxa.com/rock3/docs/hw/datasheet/Rockchip%20RK3568%20TRM%20Part1%20V1.1-20210301.pdf (Page 386) > Signed-off-by: Coia Prant Reviewed-by: Maxime Chevallier Maxime