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 C4C9AC636D4 for ; Fri, 17 Feb 2023 13:34:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: 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=yiV+zVQMfmlTDq1bkbjq8DfE/k8VEEJ7iZuakMWxSPo=; b=VfVuGFK9rKvHsl vj2078QswQgxqdCN77udRe6bWRlPVVDJZAglRlTw+36WpC5l24FEMqKDIs2O9xl5Bk5VSHD91i60T UDcz4cIkma4qLLtmJDe1GWXGyhVxN43cMwoIaihuK2OeJb+EpfkB5i97ujBAG72mBBm4UO50djxNU P5joKU464WdisIBtomwy+e82twqDw4y3dtUo1uVra5HiVYo/TVY+Hl0XzAlj+eGdO2hQzyt3ES0RE GPw10+5qJUbNT974RythcSPGoiCwETshRbc+PJ2SfZMnbDyqbCMR/AXBzDgJRczqsvdf/dtykNXKd YHGrQLC/r0IjSgTG4v1g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pT0rg-00EK1D-EI; Fri, 17 Feb 2023 13:33:28 +0000 Received: from vps0.lunn.ch ([156.67.10.101]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pT0p8-00EIy2-JB; Fri, 17 Feb 2023 13:30:51 +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=mn2YdWkFcL6Ae+Ff818yS4ufU/Ud2IoVDGKh7MUqoRQ=; b=EViK8fRXQtkgM55djQ/72gds7/ lkJP8WWagq1/cxmOvPjfhv54besDmSyxTgOLcUM0/BzKJHtCYG3IpMy35R3XwQwasnWJNDtE4juXB H8YHTZ/v3XMH6OYNLTO5jNtJ0fAnpWvhDrzwGzg1FW3OfVGPhFqSr+u8lfQJH4Uo4pJA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1pT0oX-005Hjw-FD; Fri, 17 Feb 2023 14:30:13 +0100 Date: Fri, 17 Feb 2023 14:30:13 +0100 From: Andrew Lunn To: Cristian Ciocaltea Cc: Lee Jones , Rob Herring , Krzysztof Kozlowski , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Emil Renner Berthing , Conor Dooley , Palmer Dabbelt , Paul Walmsley , Albert Ou , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Maxime Coquelin , Richard Cochran , Sagar Kadam , Yanhong Wang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-riscv@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, kernel@collabora.com Subject: Re: [PATCH 07/12] dt-bindings: net: Add StarFive JH7100 SoC Message-ID: References: <20230211031821.976408-1-cristian.ciocaltea@collabora.com> <20230211031821.976408-8-cristian.ciocaltea@collabora.com> <586971af-2d78-456d-a605-6c7b2aefda91@collabora.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230217_053050_669537_C8F95834 X-CRM114-Status: GOOD ( 19.59 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org > > I would actually say it shows we don't understand what is going on > > with delays. "rgmii" is not every often the correct value. The fact it > > works suggests the MAC is adding delays. > > > > What value are you using for starfive,gtxclk-dlychain ? > > This is set to '4' in patch 12/12. > > > Try 0 and then "rgmii-id" > > I made some more tests and it seems the only stable configuration is "rgmii" > with "starfive,gtxclk-dlychain" set to 4: > > phy-mode | dlychain | status > ---------+----------+-------------------------------------------- > rgmii | 4 | OK (no issues observed) > rgmii-id | 4 | BROKEN (errors reported [1]) > rgmii | 0 | UNRELIABLE (no errors, but frequent stalls) > rgmii-id | 0 | BROKEN (errors reported) > > [1] Reported errors in case of BROKEN status: > $ grep '' /sys/class/net/eth0/statistics/* | grep -v ':0$' Thanks for the testing. So it seems like something is adding delays when it probably should not. Ideally we want to know what. There is a danger here, something which has happened in the past. A PHY which ignored "rgmii" and actually did power on defaults which was "rgmii-id". As a result, lots of boards put "rmgii" in there DT blob, which 'worked'. Until a board came along which really did need "rgmii". The developer bringing that board up debugged the PHY, found the problem and made it respect "rgmii" so their board worked. And the fix broke a number of 'working' boards which had the wrong "rgmii" instead of "rgmii-id". So you have a choice. Go with 4 and "rgmii", but put in a big fat warning, "Works somehow but is technically wrong and will probably break sometime in the future". Or try to understand what is really going on here, were are the delays coming from, and fix the issue. Andrew _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel