From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-m32112.qiye.163.com (mail-m32112.qiye.163.com [220.197.32.112]) (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 25EE321B9FD; Sat, 31 Jan 2026 09:55:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.32.112 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769853340; cv=none; b=G69B3IZ3z0SwRCrayT021Uq6ZhjlD0sfhbq2MqfljoO34++viqWtWoxPLyDgARgbLwbnWz9DoU5WrKkNsjIuhAJDkohoOtTX4BVR11Pg2AwMKb9E8mo/lFeciA5mNrmiG9gwgOGajCW8oRKbfxdGjmsxBEXEOpl/g7GMC33YYq0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769853340; c=relaxed/simple; bh=Yw6Upyb+CWxY4Ou04WxDZ0z+wRHH51S4yIR9oJc4V5o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=UsfaEX9nkR5eOFKafyItMrPffRssmv92FlMNcCaT2MmvuO8a2hz4v74tzzzvmFNrv2KymmjNHvOXvhoaOHNBL1gVfSqCFRNk+sTW7+/9ClwOBGe7oKGRlliC2C8L51/ernXXjf9iOgBCq+XNBtc4xtLgzxf9nOyulVQzxnhRFLA= 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=fPmlXqpY; arc=none smtp.client-ip=220.197.32.112 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="fPmlXqpY" Received: from [127.0.0.1] (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 32a366f45; Sat, 31 Jan 2026 14:26:14 +0800 (GMT+08:00) Message-ID: Date: Sat, 31 Jan 2026 14:26:05 +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: Sebastian Reichel , Andrew Lunn Cc: Chaoyi Chen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Alexey Charkov , Shawn Lin , 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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-HM-Tid: 0a9c12bb0e0403abkunme89cdd3e6e3494 X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZQ0tLGFZOGkMfSU1OShgYTEtWFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSEpOTE 9VSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=fPmlXqpYaif+Alwx00473YixZd4FG1mKGYUX0cT/qaI8GyodiABrpI65MUYvdc7WDSRBI+E9+twWsYX0iXCBU4kQRIFA1hKnBG+Eo4cruwJXzniNEii4oKN3HJbUNhlcXo0+bXg9DCU8D8l8cb/uygMBWfJzuU6B4eN6LILi7w0=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=s0+sAGqB2yhj2oDmerbSlM2FR61cb3QdCFDcKvvINYo=; h=date:mime-version:subject:message-id:from; On 1/22/2026 11:16 AM, Chaoyi Chen wrote: > 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. > If "rgmii-id" is set, the RTL8211F driver adds the 2ns delay: [0] https://elixir.bootlin.com/linux/v6.19-rc5/source/drivers/net/phy/realtek/realtek_main.c#L602 Sebastian, could you try testing how much extra delay the GMAC still needs to add for the ROCK4D to work correctly, assuming the PHY already has a 2 ns delay when "rgmii-id" is set? -- Best, Chaoyi