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 445B1248F64; Mon, 17 Nov 2025 13:23:22 +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=1763385805; cv=none; b=mF5we+tNwxcpbIiwyQ0Y1xEHmAKqo4aZuhzFjppF1RV+tRCsdW14FYOJy9+26xSZOs1BNdHx0WT2pWBXCCYW0X0Im1cNzGtbttf0JR3M/kev3pREb/TAJ+SkehFaFb22WjzgVrb6GMzFeNYSTu72O2FifCeopseWHlIZUT08Zsw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763385805; c=relaxed/simple; bh=0xRsYfRwwvZEOnSLuS4fMdOkAxgzpZ9zP/vfsp2Pub0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sUOFSNBY+Y/YdxqHVSuM8bCCjZ06W7PX6hZFLKfC1PhNEOW/qZVO7EWHJX838ecND5X2OMwhRp2r9MVeiIx1KdRssJbIUfeEhBURTjKitqUgyjVvrjIhm2phbuYrLLd2ZYvXxHqKyi3aG7NjqVVNTrkC756iynYKbxPQ9frAjr0= 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=YtTwtdV6; 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="YtTwtdV6" 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=xqejCIGkJ5sENGSMceu9HHpQdlX0H+SUk9LYUYfeBpo=; b=YtTwtdV6eZ8JCI4+9pdFjY8Piy lj6BTQ8GUJUK8FN99LBEnNL1zEpX5kyOOftsUZEPz89wSr+WlcItKVLoKPNKAqjH/tMGro6a4busl 58X+/nZ4iA/WVul5b0f/e3jgncsm03s42qI8vaDUKw5ZcCSJ09Pc0oq4UOhckK4NN2tc=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1vKzC5-00EF28-Ir; Mon, 17 Nov 2025 14:22:57 +0100 Date: Mon, 17 Nov 2025 14:22:57 +0100 From: Andrew Lunn To: Wei Fang Cc: "linux@armlinux.org.uk" , "hkallweit1@gmail.com" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" , "eric@nelint.com" , "maxime.chevallier@bootlin.com" , "imx@lists.linux.dev" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] net: phylink: add missing supported link modes for the fixed-link Message-ID: <9f9df3b3-ea08-43d7-8075-68b4fe19e6a0@lunn.ch> References: <20251116023823.1445099-1-wei.fang@nxp.com> <30e0b7ba-ac60-49e0-8a6d-a830f00f8bbc@lunn.ch> Precedence: bulk X-Mailing-List: linux-kernel@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: On Mon, Nov 17, 2025 at 03:23:05AM +0000, Wei Fang wrote: > > This also seems like two fixes: a regression for the AUTONEG bit, and > > allowing pause to be set. So maybe this should be two patches? > > As Russell explained in the thread, one patch is enough. > > > > > I'm also surprised TCP is collapsing. This is not an unusual setup, > > e.g. a home wireless network feeding a cable modem. A high speed link > > feeding a lower speed link. What RTT is there when TCP gets into > > The below result is the RTT when doing the iperf TCtestP > root@imx943evk:~# ./tcping -I swp2 10.193.102.224 5201 > TCPinging 10.193.102.224 on port 5201 > Reply from 10.193.102.224 (10.193.102.224) on port 5201 TCP_conn=2 time=1.004 ms > Reply from 10.193.102.224 (10.193.102.224) on port 5201 TCP_conn=3 time=0.958 ms With 1ms ping times, you don't have buffer bloat problems, so that is not the issue. I still think you need to look at this some more. Both Russells comments about it potentially blocking traffic for other ports, and why TCP is doing so bad, maybe gets some traffic dumps and ask the TCP experts. Andrew