From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 AB51522A1D5; Thu, 18 Sep 2025 15:05:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758207906; cv=none; b=uo1Dk9SrixpRmgm1l7O8m65zFADPEWcAiAHVQtRE7YAgQ3j9dQEfTqDqWTcDyG8P2fRO0UoATAKa0gVaS8QHPnbPn6PtMju1KOAoLDHQEV+yLtnID9TZfexP9vXUb6W5g+h+5+U1400d1K1LEixGRnCATNsUy7PYVDXhYkj1ns0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758207906; c=relaxed/simple; bh=dEh6BfjHPJCDZQNyVxEP0Gyi/kZdfBsir4jzEInAR9U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=o7W9upFSL9elNV7YK3ixFL1niHRd3TpVyhO2AdxFxlPb5lppWlo21HV36FnZc22xluBsLAl0eTrIdl6xbws3wYSsvC66IeIYnX78OSZGO9ONpIBy7mc1DjS0QRgerBhyDgg4+u0LolKJln2uXm2vCF6KD8ppv+7/tYkRtesGngQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=2Mg6dsQR; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="2Mg6dsQR" 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=gT7EyJhqaGT1c/vVbat3yyZR0Yh/jcDyJmsQcPvAhhs=; b=2Mg6dsQRTBgEVP1SD38awP1HMR VvKK0efTP0JUtG5xvhbIVACkueM+2moVFWtAlmpRQfbaX166ZQBeUMz63JIUb4QIolAa6aTlcBmdP E50ZUVM0uxw1NFBK57Eg0qCdzKXOiyM4dwi4vS3tzX+voRwq5MUK3j+7fA8h8V9Vy8QA=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1uzGBr-008q5n-Ct; Thu, 18 Sep 2025 17:04:55 +0200 Date: Thu, 18 Sep 2025 17:04:55 +0200 From: Andrew Lunn To: David Jander Cc: Jonas Rebmann , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Liam Girdwood , Mark Brown , Shengjiu Wang , Shawn Guo , Sascha Hauer , Fabio Estevam , Pengutronix Kernel Team , Vladimir Oltean , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Lucas Stach , Oleksij Rempel Subject: Re: [PATCH v2 3/3] arm64: dts: add Protonic PRT8ML board Message-ID: <7f1d9289-4102-4db9-a2bb-ff270e8871b7@lunn.ch> References: <20250918-imx8mp-prt8ml-v2-0-3d84b4fe53de@pengutronix.de> <20250918-imx8mp-prt8ml-v2-3-3d84b4fe53de@pengutronix.de> <20250918165156.10e55b85@erd003.prtnl> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250918165156.10e55b85@erd003.prtnl> > Yes, unfortunately the SJA1105Q does not support PAUSE frames, and the i.MX8MP > FEC isn't able to sustain 1000Mbps (only about 400ish) due to insufficient > internal bus bandwidth. It will generate PAUSE frames, but the SJA1105Q > ignores these, leading to packet loss, which is obviously worse than > restricting this link to 100Mbps. Ironically both chips are from the same > manufacturer, yet are incompatible in this regard. Thanks for the explanation. Maybe add a comment that the bandwidth is limited due to the lack of flow control resulting in packet loss in the FEC. Anything which looks odd deserves a comment, otherwise somebody will question it.... Andrew