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 C6BAAC369AB for ; Thu, 24 Apr 2025 14:27:47 +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:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8XYpVhm52DVam+YizY27gQ41KkS4MOi3Qkd0CbVTMIU=; b=J/iYTV6ccl7443YCRf9yN7X9kx g+JyIo+08sJVBiSTafXZWydYXMzxBW5JqaDZTqQZ3S+b0WA6kq7dboacDQleRqWMpOqWMKVOLo8gh KBmoAWWWmy8ZqLLI2AWfoEw9tQUzb501MmZoNfaeo3nCVH7wh433jBt9V4337Nx+hBcHKK7l1FNuL BcQQyWowNkAwo1YoWKVQCpgNO5wgd9HczuRhSg3VtScSxD16PyXLSO3eOD0xnyH8jZgsgQpFbTN2j JWERXF3YK4y5ZEtm6ik9rVIwPzQLYgrDsOuP+qc5+Mm9p56HY75aYiNIcUHfhNUli+JyXycd3c1CV PWijwRvA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7xYA-0000000ENSI-3Uip; Thu, 24 Apr 2025 14:27:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7wUv-0000000EAWQ-1DIc for linux-arm-kernel@lists.infradead.org; Thu, 24 Apr 2025 13:20:15 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6DC8F1063; Thu, 24 Apr 2025 06:20:07 -0700 (PDT) Received: from donnerap.manchester.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9A2CC3F66E; Thu, 24 Apr 2025 06:20:09 -0700 (PDT) Date: Thu, 24 Apr 2025 14:20:06 +0100 From: Andre Przywara To: Andrew Lunn Cc: Yixun Lan , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Maxime Ripard , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 4/5] arm64: dts: allwinner: a527: add EMAC0 to Radxa A5E board Message-ID: <20250424142006.021d6ab4@donnerap.manchester.arm.com> In-Reply-To: <6e9c003e-2a38-43a7-8474-286bdb6306a0@lunn.ch> References: <20250423-01-sun55i-emac0-v1-0-46ee4c855e0a@gentoo.org> <20250423-01-sun55i-emac0-v1-4-46ee4c855e0a@gentoo.org> <20250424014120.0d66bd85@minigeek.lan> <20250424100514-GYA48784@gentoo> <6e9c003e-2a38-43a7-8474-286bdb6306a0@lunn.ch> Organization: ARM X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.32; aarch64-unknown-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250424_062013_376575_B95668D6 X-CRM114-Status: GOOD ( 16.75 ) 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, 24 Apr 2025 14:19:59 +0200 Andrew Lunn wrote: Hi Andrew, > > I'd not bother to try other combinations, and just stick to vendor's > > settings > > Vendors get stuff wrong all the time. Just because it works does not > mean it is correct. And RGMII delays are very frequently wrong because > there are multiple ways to get a link which works, but don't follow > the DT binding. Speaking of which: do you know of a good method to verify the delay timing? Is there *something* which is sensitive to those timings and which can be easily checked and qualified? I just tried iperf3 yesterday, but didn't spot any real change in the numbers when toying with those delay values. As mentioned in the other email, we can easily hack the values at runtime, so if there is a way to get some "quality" value, this could even be automated. Thanks, Andre