From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="auW2A490" Received: from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::226]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 162A2D56 for ; Fri, 17 Nov 2023 07:09:32 -0800 (PST) Received: by mail.gandi.net (Postfix) with ESMTPSA id 649A6C0009; Fri, 17 Nov 2023 15:09:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1700233771; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=UXuNjUVN/i3SDyFOHUKZtsOeHvcsrFLBDRIHM+JisT8=; b=auW2A490Mc6Ork0k0BQPL0UgqqtwKKXb0WYiRcnxmEtIr3/zW3sqJ/OC7+gk8K1crrHu5L ukiJSC7kDfuzGKpa9Vd6TKvKJFWquw4yYbq99M01GuYu/STpuT2fkD5v3AjoBt5Ephemwq etThRVgND/bsidndu8yUSLWrNOghB3qsnUxQyqaGeVStdiH+Q8diZx9DzVdz58YxpHdPJt BuHw6UKAplKQcZi7Gx8qrUxnXjaUdHlPLPCdJ2/UVJbyxc0AhM4quzDTc7itr7p/01EQVY YSJ6NXlz8EhJEjuYUXhYYvmKMv3g2d2QQ0w9yg08Frl/t7DSNCY4eBN3+h/86A== Date: Fri, 17 Nov 2023 16:09:28 +0100 From: Miquel Raynal To: Andrew Lunn Cc: Stephen Hemminger , Wei Fang , Shenwei Wang , Clark Wang , Russell King , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-imx@nxp.com, netdev@vger.kernel.org, Thomas Petazzoni , Alexandre Belloni , Maxime Chevallier Subject: Re: Ethernet issue on imx6 Message-ID: <20231117160928.04ba5359@xps-13> In-Reply-To: <20231027225836.11594bd5@xps-13> References: <20231012193410.3d1812cf@xps-13> <8e970415-4bc3-4c6f-8cd5-4bbd20d9261d@lunn.ch> <20231012155857.6fd51380@hermes.local> <20231013102718.6b3a2dfe@xps-13> <4736f0df-3db2-4342-8bc1-219cbdd996af@lunn.ch> <20231027225836.11594bd5@xps-13> Organization: Bootlin X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-GND-Sasl: miquel.raynal@bootlin.com Hello, > I've investigated this further and found a strange relationship with > the display subsystem. It seems like there is some congestion happening > at the interconnect level. I wanted to point out that your hints helped > as I observed that the above counters were incrementing as expected, > but the packets were just not sent out. My interpretation is some > kind of uDMA timeout caused by some hardware locking on the NIC by > the IPU which cannot be diagnosed at the ENET level (the interrupt > handler is firing but the skb's are not sent out, but we have no > error status for that). >=20 > Here is the link of the thread I've just started with DRM people in > order to really tackle this issue: > https://lists.freedesktop.org/archives/dri-devel/2023-October/428251.html For future reference, the thread mentioned above unfortunately did not lead to any discussion (I admit it's not a common topic though) and further investigation pointed at the DDR configuration. I had a hard time making a link between the reset pad of the DDR controller being misconfigured and the Ethernet drop rate, I still fail to do, but in practice this very little change apparently had a significant impact and totally solved our issue: https://lore.kernel.org/u-boot/20231117150044.1792080-1-miquel.raynal@bootl= in.com/ Thanks to all of you for your help and feedback, Miqu=C3=A8l