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 3A20DCCFA18 for ; Tue, 11 Nov 2025 23:54:53 +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=D9+lh4xSPJQ+Bq75r64J2U542l0W+0x/XBxsmjqE13s=; b=FEaer7Qn6D3P8EbhuP1vr6m3yP inb8grDAFxVqB70EHpFz6vEGD9jn8PrPAUQpSMOe7HcapxY91EfOKQPDTN9X2ew2Bn+mCQyVMGFnW Q82NzZ7tLqRutckgILHjULhj3BkGdYAS+CbFdS4cnWkd+X1JtHSAqB5jUYm1G8EZPeppuWTfj9obj uh9moQ3gugOilG3caGXtm1tyohSmv38otfFwDisRL0znMOox4yJm2MF9JVsifiXDkMTcrzad6wdte zTAwT4L3O4etAFPUK9XLX/RlDWhAki98J8fLwZu7NAyqoP/UXR3k+lgs7JY36axJxpz6O4n3iwAgC ZKOKAigw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIyCD-00000007uJO-3vUh; Tue, 11 Nov 2025 23:54:45 +0000 Received: from perceval.ideasonboard.com ([213.167.242.64]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIyCB-00000007uIi-3vW9 for linux-arm-kernel@lists.infradead.org; Tue, 11 Nov 2025 23:54:45 +0000 Received: from pendragon.ideasonboard.com (82-203-161-95.bb.dnainternet.fi [82.203.161.95]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 3D5BC16A7; Wed, 12 Nov 2025 00:52:42 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1762905162; bh=K+GlrNLwbthHk2+M7wdXI3Vz5I8fexlgTGx+hnLNPhk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HZSDmkPI5wPAxOkKGz7gHhkhK6omEHTUoLvFfE5E5ju+wKwvF57B1DqG7Ux6FhXKN 4yLlo7VmvPFSNzsulSQYjpPApuEdYlj8AiAHMVYBragYabbwEUa3ZtKhk6uoLwB09r ytxBPNbklgzlGl9tqb4+xKOhAemJI97lLsiub9OE= Date: Wed, 12 Nov 2025 01:54:34 +0200 From: Laurent Pinchart To: "Russell King (Oracle)" Cc: Oleksij Rempel , Emanuele Ghidoli , 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 , Catalin Popescu Subject: Re: [PATCH] arm64: dts: imx8mp-debix-model-a: Disable EEE for 1000T Message-ID: <20251111235434.GA25874@pendragon.ideasonboard.com> References: <20251026122905.29028-1-laurent.pinchart@ideasonboard.com> <20251027234648.GC24987@pendragon.ideasonboard.com> <20251028071817.GX13023@pendragon.ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251028071817.GX13023@pendragon.ideasonboard.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251111_155444_113401_E24E587F X-CRM114-Status: GOOD ( 36.12 ) 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 Tue, Oct 28, 2025 at 09:18:17AM +0200, Laurent Pinchart wrote: > (CC'ing Catalin) > > On Tue, Oct 28, 2025 at 12:57:55AM +0000, Russell King (Oracle) wrote: > > On Tue, Oct 28, 2025 at 01:46:48AM +0200, Laurent Pinchart wrote: > > > On Mon, Oct 27, 2025 at 03:13:51PM +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. > > > > > > > > We've finally got to the bottom of what's going on here. Please try > > > > this patch (it's building locally, but will take some time because > > > > I'd wound the tree back to 6.13 and 6.14, so it's going to be a full > > > > rebuild.) Thus, there may be compile bugs remaining. > > > > > > I've applied it on top of > > > > > > I've started with a branch based on v6.18-rc3 plus "[PATCH net-next 0/5] > > > net: stmmac: more cleanups" ([1]) and "[PATCH net-next v2 0/6] net: add > > > phylink managed WoL and convert stmmac" ([2]) to make the patch apply > > > cleanly. > > > > > > [1] https://lore.kernel.org/all/aO_HIwT_YvxkDS8D@shell.armlinux.org.uk/ > > > [2] https://lore.kernel.org/all/aPnyW54J80h9DmhB@shell.armlinux.org.uk/ > > > > > > The base branch exhibits the interrupt storm issue. The patch > > > unfortunately doesn't fix it. > > > > So it's highly unlikely that your problem is the same as Emanuele's. > > > > Do you know when the interrupt storm behaviour started? If not, I'd > > suggest testing 6.13 and 6.14 as a starting point to see whether > > the phylink-managed EEE conversion is involved. > > I can't test it right now (no access to hardware during daytime for this > week), but if I recall correctly my colleague Stefan Klug bisected the > issue to > > commit dda1bc1d8ad13672c2728eedee0dd02d27a5314a > Author: Catalin Popescu > Date: Mon Oct 7 15:44:24 2024 +0200 > > arm64: dts: imx8mp: add cpuidle state "cpu-pd-wait" > > So far, only WFI is supported on i.MX8mp platform. Add support for > deeper cpuidle state "cpu-pd-wait" that would allow for better power > usage during runtime. This is a port from NXP downstream kernel. > > Signed-off-by: Catalin Popescu > Signed-off-by: Shawn Guo > > I didn't notice it at the time because my board was connected to a > switch that didn't support EEE. I can confirm that reverting that commit makes the issue disappear. So we're dealing with an interrupt storm that occurs when all three of the following conditions are true: - cpu-pd-wait is enabled - EEE is enabled - the peer also supports EEE Furthermore, I tried counting bits from all the interrupt status registers I could find. The count of MTL_INTERRUPT_STATUS Q0IS to Q4IS bits is very high, and so are the DMA_CH0_STATUS TBU and ETI bits. The debix board's DT doesn't specify a multi-queue setup, so only channel 0 gets processed in stmmac_dma_interrupt(). I thought that could explain why Q1IS to Q4IS stay set (but not why Q0IS also has a high count, or why Q1IS to Q4IS are set in the first place), and enabled multi-queue support in DT by copying the imx8mp-evk configuration. I then see lots of non-zero DMA_CH1_STATUS, DMA_CH2_STATUS and DMA_CH4_STATUS values (but DMA_CH3_STATUS stays 0 all the time), but sadly this doesn't fix the interrupt storm. I don't know how much sense all this makes, and I'm sorry if the above information is unclear, incomplete or completely wrong, my experience with the DWMAC is very limited. I don't think I can debug this further and figure out the root cause unassisted in a reasonable amount of time, so I'd like to merge disabling EEE as a workaround for the time being, unless someone has any idea of what I could test next. I'll submit a v2 of this patch with an updated commit message. -- Regards, Laurent Pinchart