From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 8311A3C084 for ; Fri, 27 Oct 2023 20:58:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="jb/rCVvC" Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::228]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 919C61AA for ; Fri, 27 Oct 2023 13:58:41 -0700 (PDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id 012261BF203; Fri, 27 Oct 2023 20:58:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1698440319; 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=mOCsjhN2awknGo5pBlXRMM+M86Or5ct0FJt+fQPYItw=; b=jb/rCVvC0bUZIVDk76vxqa5l84U5AlmuVSm0uxO1Ymb/JI+N6EF3twM4m3Y/b3QEtNFlva R7adzus77K9z/T82BdpO6UKr4C+0mAQ89i7P9v90WR85vcd8WzHUcVvCvmjTGIiiBdH9yv W6Q78d6NzpKvRmtSpTs1wn7hGbZkwLKJK48+H7+kp1N5uMfVFvjjWFgh6z55G0CXKLH5F6 KohheqQlb2rTfYPAxqpctBHwVaZOnRQBN6VXu0sfxHg5vEkT4ymLdcVxnRF85QhsY5Mrgk Uw/4ahX/8PnvXxGW3Bu7koEKS6b7T51cXKpTZ1rGBX66BrBMgXWwveuSX/cYNw== Date: Fri, 27 Oct 2023 22:58:36 +0200 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: <20231027225836.11594bd5@xps-13> In-Reply-To: <4736f0df-3db2-4342-8bc1-219cbdd996af@lunn.ch> 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> 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 Hi Andrew, andrew@lunn.ch wrote on Fri, 13 Oct 2023 17:51:20 +0200: > > # ethtool -S eth0 > > NIC statistics: > > tx_dropped: 0 > > tx_packets: 10118 > > tx_broadcast: 0 > > tx_multicast: 13 > > tx_crc_errors: 0 > > tx_undersize: 0 > > tx_oversize: 0 > > tx_fragment: 0 > > tx_jabber: 0 > > tx_collision: 0 > > tx_64byte: 130 > > tx_65to127byte: 61031 > > tx_128to255byte: 19 > > tx_256to511byte: 10 > > tx_512to1023byte: 5 > > tx_1024to2047byte: 14459 > > tx_GTE2048byte: 0 > > tx_octets: 26219280 =20 >=20 > These values come from the hardware. They should reflect what actually > made it onto the wire. >=20 > Do the values match what the link peer actually received? >=20 > Also, can you compare them to what iperf says it transmitted. >=20 > From this, we can rule out the industrial cable, and should also be > able to rule out the receiver is the problem, not the transmitter. 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). 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 Thanks, Miqu=C3=A8l