From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 5CB59377AA7 for ; Thu, 1 Oct 2026 13:33:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790861618; cv=none; b=QMmNJXkmxQxETwN6zmAPhUssB2U2RnPV/1Z2jWIvejTe1SMdL7FLHst6JWB/6Mel1NQ5MNI0t3QSq7p7av0mY0rlSUmSAUkAl1bwBTthtf81oNyeBQU99yjxdCTlLPTMQa1MCAdYOTvyRau0e7y+O0oQdZSCHlWXOJz9MF3u1Go= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790861618; c=relaxed/simple; bh=sYp4IODDRE/oqGxfiwL0E5qPsGe6BaznATzQ1246n/4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=WCq/xEDHWZET7PKxiC/luMRRS1MAYzFbLkj9HM647WZvbTVC4WqsNr8uPwDBhoyeGoC5giCcnRYCbt8X70xpQxhmyfSidSyvh7RhlGYSLxVBJl7S3VIhH91V8p00Ver3EcGMwQO2rZsqo1OETtBkWJGlEmu/8VSkSzXZu1y/07w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=VA8aJFvK; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="VA8aJFvK" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=ZISLUrZjX4iOiIppbllyKD1bMSKBGdCj0f514qP2Ki4=; b=VA8aJFvKOX5a5dHnydfnZAiZoZ xsVbFTkY0Vsp2WeSQcCPHm3bnBB/EXnPPIcEjYhg72PBhEysEIrd2GedfdD7rMFFIgi1qEfpupnGM zzruX6GHY60XJaPIr18aS6ZmV2SAoYWQo6rLQPPWOBbeZBuJjcZdK+lN3mG2iXkfimZI=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1xCGud-008OTL-Sr; Thu, 01 Oct 2026 15:33:27 +0200 Date: Thu, 1 Oct 2026 15:33:27 +0200 From: Andrew Lunn To: BG9OXA Cc: linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Heiko Stuebner Subject: Re: [PATCH v2 0/2] arm64: dts: rockchip: add ALIENTEK QuarkPi-CA2 Message-ID: <80eceb66-b573-463a-a577-30ba5793dbc4@lunn.ch> References: <179051708448.31632.16350193430088134671@163.com> <179086062104.25951.4172888328376175948@163.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <179086062104.25951.4172888328376175948@163.com> On Thu, Oct 01, 2026 at 09:17:01PM +0800, BG9OXA wrote: > Hello Andrew, > > Following up on the phy-mode point, with the measurements I promised. > > I ran three 15-minute runs at full rate in both directions on this board > (rk_gmac-dwmac + YT8531 PHY, iperf3, 900 s per direction), rebooting > between runs so each configuration was fresh: > > mode tx_delay rx_delay board->host host->board retrans > rgmii-rxid 0x2f 0x00 922 Mbit/s 939 Mbit/s 0 > rgmii 0x2f 0x00 922 Mbit/s 939 Mbit/s 0 > rgmii-id 0x00 0x00 918 Mbit/s 939 Mbit/s 224 > > The MAC error counters (rx/tx errors and drops) stayed at zero in all > three runs, and the link came up at 1000 Mb/s Full duplex every time. > > So plain "rgmii" with the delay added on the MAC side behaves exactly > like the rxid form, and the "rgmii-id" run - where both sides add the > delay - is the only one that shows retransmissions. That matches your > point that only one side should add the delay. I have changed 2/2 to > phy-mode = "rgmii" and dropped the rxid form: the RGMII traces on this > board are ordinary length, so nothing in the PCB asks for an extra RX > delay. Did you read https://elixir.bootlin.com/linux/v6.15/source/Documentation/devicetree/bindings/net/ethernet-controller.yaml#L287 phy-mode describes the PCB. 'rgmii-id' says the PCB does not have extra RX/TX delays. So 'rgmii-id' is correct here. Please spend some time to understand what delays are being added where, and how you can get to rgmii-id without any retransmissions. Andrew