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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E7E7ACA5FD2 for ; Thu, 1 Oct 2026 13:33:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ZISLUrZjX4iOiIppbllyKD1bMSKBGdCj0f514qP2Ki4=; b=SIlc5sPhw5jYricyCgCIzFEqHU VskBI5yHF1Qjp03+5tQklICBUqNVBk9HDVu/QSkVLO3v+9Of6aeZpQupf1pGgsW42geR8MDmQcsxe M0xYD06bmkyK9mkfD7AAyGM22489vcR1s2lDsKnq5lYQxQFBI5ML+XOaajxu+omt/pT83hYVQ7htu moGVq0w5tQ+8NZD/5jnvhx07cWOhhcnm3gPAObkYr/1FiCiMdz1ChtB0VcLi2qY9nUKEVkz9wuHl4 VeKOZ/4ZVeDQ3csDUZlrrWc5xA9QI4RT/uyBhEM1tTCK0UIANp71quV+vLFbmlQG13Hq10skuBje7 IIznCWig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCGul-00000009FLs-1F2g; Thu, 01 Oct 2026 13:33:35 +0000 Received: from vps0.lunn.ch ([156.67.10.101]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCGui-00000009FKU-0AKQ; Thu, 01 Oct 2026 13:33:34 +0000 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <179086062104.25951.4172888328376175948@163.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261001_063332_077366_5B280AFE X-CRM114-Status: GOOD ( 14.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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