From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 C14DF2652BD for ; Mon, 27 Oct 2025 09:34:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761557643; cv=none; b=GqgmR1icBlZxS6qstxWIuhozO3yZ90LYE5X+CP2+xz2UD8+ZXYyljw9PE68wv+9Ym00ex4rxRQHGv2EJ69n/7oy25moFmCub85JfB2yacS/IbISUkp3QNejt5K7Nla6KMnVtkTOuSVP8l5JkhM/54uNu2bhP9b77mRWf0y6bBJk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761557643; c=relaxed/simple; bh=JWOTEzsnqe2ZVX69WMnwkdkU+ZQ82vlW3C/Ncaoe77o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UiG9fFUWYLquEmK2wzxPRWlpiQgS4E5nUiIj6fmDLDA8TOZwMQJZ4Bi6sldXRnIdswjCtTDxSF9uOQaJ6bivsHSqb22dmi1Urw8K1ISQ9bn3eAfZ9PrFk4qWVsmugzTaYO1x812+GegTa3RKfxsIhk9z596T8vsOJpHFWE4CRvE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=RfpAy3rG; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="RfpAy3rG" Received: from pendragon.ideasonboard.com (unknown [193.209.96.36]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id E04621661; Mon, 27 Oct 2025 10:32:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1761557532; bh=JWOTEzsnqe2ZVX69WMnwkdkU+ZQ82vlW3C/Ncaoe77o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RfpAy3rGzg7hBJpFqUe7Fcpd2joSB2//BoH9daa4FQ+HnQfqX8G+sj8/R00TFllqI cQMwAYuX5R2+RasSArIE2mwNRaD6Kf/eEFGu/laS4ld6sJh9OnTie2QTLPbOQUxlDQ FTH363BCa5sL1N+W5wxr8+ivFHTA2jiaswQSmNyg= Date: Mon, 27 Oct 2025 11:33:46 +0200 From: Laurent Pinchart To: "Russell King (Oracle)" Cc: devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Daniel Scally , Kieran Bingham , Stefan Klug , Conor Dooley , Fabio Estevam , Krzysztof Kozlowski , Pengutronix Kernel Team , Rob Herring , Sascha Hauer , Shawn Guo , Emanuele Ghidoli Subject: Re: [PATCH] arm64: dts: imx8mp-debix-model-a: Disable EEE for 1000T Message-ID: <20251027093346.GB1544@pendragon.ideasonboard.com> References: <20251026122905.29028-1-laurent.pinchart@ideasonboard.com> Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hi Russell, On Mon, Oct 27, 2025 at 09:07:32AM +0000, Russell King (Oracle) wrote: > On Sun, Oct 26, 2025 at 02:29:04PM +0200, Laurent Pinchart wrote: > > Energy Efficient Ethernet (EEE) is broken at least for 1000T on the EQOS > > (DWMAC) interface. When connected to an EEE-enabled peer, the ethernet > > devices produces an interrupts storm. Disable EEE support to fix it. > > As this is the second problem that has been reported recently, please > bisect the conversion of stmmac to phylink managed EEE support and see > whether there is anything in that which is causing this. Emanuele Ghidoli has bisected this to commit 2c81f3357136 ("net: stmmac: convert to phylink PCS support"), as reported in [1]. I can test that commit and the commit just before tonight. [1] https://lore.kernel.org/all/341f56de-9dde-4c44-9542-b523e1917dcb@gmail.com/ > Please also confirm that EEE was enabled (as soon through ethtool) > prior to stmmac's conversion (I believe it was due to this code that > was present in stmmac_init_phy(): > > - if (priv->dma_cap.eee) > - phy_support_eee(phydev); > - > ret = phylink_connect_phy(priv->phylink, phydev); > > > The exact reason for the interrupt storm is unknown, and my attempts to > > diagnose it was hindered by my lack of expertise with DWMAC. As far as I > > understand, the DWMAC implements EEE support, and so does the RTL8211E > > PHY according to its datasheet. What each side does exactly is unknown > > to me. One theory I've heard to explain the issue is that the two > > implementations conflict. There is no register in the RTL8211E PHY to > > disable EEE on the PHY side while still advertising its support to the > > peer and relying on the implementation in the DWMAC (if this even makes > > sense), so disabling EEE is the only viable option. > > > > This patch is likely a workaround, but it fixes ethernet usage on the > > board, so it's in my opinion worth being merged. If someone with better > > knowledge of EEE and DWMAC, as well as an interest in getting it working > > properly on the Debix board, wants to submit additional patches to drop > > eee-broken-1000t, I will be happy to test them. > > The changes to stmmac have been tested on nVidia Jetson Xavier NX, > which uses RGMII with dwmac4 and a RTL8211F PHY, connected to a Netgear > GS108 switch. It seems to be the same that your board is using similar. Very similar indeed, with a RTL8211E instead of the RTL8211F. > I will re-test today. Thank you. -- Regards, Laurent Pinchart