From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m4920.qiye.163.com (mail-m4920.qiye.163.com [45.254.49.20]) (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 9186F30BF63; Thu, 22 Jan 2026 03:21:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.254.49.20 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769052118; cv=none; b=qSfGN2dfgvdQZ+SothrAG/Eu2ZnEDPnTzDO9Jr5igjNs1+h7Ghpz+EabtzGcrNca+aYXmBGfB2RO0v78qvfX4IxnMy170ZlzaRZRsH0huZVabL0Cf/VUtrUkpYJnDfDf053Jnp4fQKyl+PzxvtaCoUiK+iY/H+GTJ6ZBS7ls2EE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769052118; c=relaxed/simple; bh=MEn+CSymw1fKSeilyCPnPMjMFivUkBIqcDjVR/9hHDM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tZmT3F1vZedgYEhr7H0HaVJ27lAvBAo1rd1YDjSXtNPOA8qLxu9z8GSrcy5JIaDc7/bYPR7CBSwlUB6tBEz7Mp78xcjLypaQ+jhm5tdB1m7tYsaRlejy/99yrVNAgqc2vLbfNlC3I9HlYUaEVA5RcDrNDz6yItPTywgv50LgeKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com; spf=pass smtp.mailfrom=rock-chips.com; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b=CWuMnatJ; arc=none smtp.client-ip=45.254.49.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b="CWuMnatJ" Received: from [127.0.0.1] (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 31880f758; Thu, 22 Jan 2026 11:16:42 +0800 (GMT+08:00) Message-ID: Date: Thu, 22 Jan 2026 11:16:40 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/3] arm64: dts: rockchip: Change gmac phy-mode to rgmii-id for rk3576 evb1 To: Andrew Lunn , Chaoyi Chen Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Alexey Charkov , Shawn Lin , Sebastian Reichel , Andy Yan , Nicolas Frattaroli , Detlev Casanova , Stephen Chen , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260121031548.402-1-kernel@airkyi.com> <20260121031548.402-2-kernel@airkyi.com> <81D509A8F65F0243+c7b58aef-95a4-4f2a-a423-7e8b2c0bbeab@airkyi.com> <55c9b522-e43d-4df3-9f7a-3f2976b72854@lunn.ch> Content-Language: en-US From: Chaoyi Chen In-Reply-To: <55c9b522-e43d-4df3-9f7a-3f2976b72854@lunn.ch> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-HM-Tid: 0a9be3b44a0503abkunm4f6e7110cdce0 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZQ01NH1YeHksfTR9IHU9KSB5WFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSU9PT0 hVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=CWuMnatJ8Tcc1M4hC3AcKcGHbh93rgCX1uDfNICI078TwKATK3jjawFmBnnprZV8+FUIjouoLASDsgfiwDcGuOmEBWvt9SLMAz+vONf9o2hWM3syTXqUckq8GhrtlKd2wGAdFuWWiKWZfKnzWjlIoOzWBp34eK7K5PifJNXwFLQ=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=otU8zUr9ysKQV+4+LBuLVMkqTGH9KAp1Ay6GIjsLfwE=; h=date:mime-version:subject:message-id:from; Hi Andrew, On 1/22/2026 10:40 AM, Andrew Lunn wrote: > On Thu, Jan 22, 2026 at 09:38:17AM +0800, Chaoyi Chen wrote: >> Hi Andrew, >> >> On 1/21/2026 8:55 PM, Andrew Lunn wrote: >>>> @@ -721,6 +719,7 @@ rgmii_phy0: ethernet-phy@1 { >>>> reset-assert-us = <20000>; >>>> reset-deassert-us = <100000>; >>>> reset-gpios = <&gpio2 RK_PB5 GPIO_ACTIVE_LOW>; >>>> + tx-internal-delay-ps = <1950>; >>> >>> The PHY should add 2000ps, as required by the RGMII standard. The >>> difference is so small there is no need for tx-internal-delay. >>> >> >> Thank you for the clarification. I chose 1950 here because I find that >> the MotorComm yt8xxx Ethernet PHY binding only offer the options of >> 1950 or 2100. >> >>> In most cases, 'rmgii-id' should be sufficient, unless the PCB is >>> badly designed. >>> >> >> I suspect the ROCK 4D board might be an exception. Sebastian once >> reported that it wouldn't work properly under "rgmii-id". Well, I'm >> not sure what strategy to adopt in this case. > > Please check the report. And also, check what the PHY is doing for > delays if you don't specify the property. Is it defaulting to near > 2000ps? > It is RTL8211F PHY. The origin report is here: https://lore.kernel.org/all/20250724-rk3576-rock4d-phy-timings-v1-1-1cdce2b4aca4@kernel.org/ The RTL8211F binding doesn't provide any indication of the default delay value. I'll checking datasheet to see if it's mentioned there. -- Best, Chaoyi