From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailscanner.iro.umontreal.ca (mailscanner.iro.umontreal.ca [132.204.25.50]) (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 5347C285C8D for ; Wed, 3 Sep 2025 16:20:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=132.204.25.50 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756916410; cv=none; b=O4FXbvsqJxHkrXC7aArQmG79Xblk78adtdXgFGWnOYfIg1+Hy1dfrE40OMrtCY8dpgQIgo+X+hi/5xHbFaj9oQ8jt6dKtUnQaas5Pz4OP5EdNG8svgfLQEFL1Koc0wcjj6ix9+GDqgxchTvno/cADaCsLYQXNuSv8FWIS88vGII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756916410; c=relaxed/simple; bh=SUcQePGmeHCu/WKS3/JshufknJE7fwotww7qDUGYGro=; h=From:To:Cc:Subject:In-Reply-To:Message-ID:Date:MIME-Version: Content-Type; b=VMXAERupV9BQsqcQHWu0Sou140cXWr3f1Tb1r8KuCWAOWWGClOaTnOq2x6TrrJum1ZMhOtONBma6m4XBV4skE/uRmvMYTFAtLyHucONB+javhqLLnDV+GoFfhaMCaYD1AvW5lP3GaQvwXU9p46P9F0UVZtThfs6ud3OIJBCC8Tg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=iro.umontreal.ca; spf=pass smtp.mailfrom=iro.umontreal.ca; dkim=pass (2048-bit key) header.d=iro.umontreal.ca header.i=@iro.umontreal.ca header.b=mAGl66lS; arc=none smtp.client-ip=132.204.25.50 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=iro.umontreal.ca Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iro.umontreal.ca Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=iro.umontreal.ca header.i=@iro.umontreal.ca header.b="mAGl66lS" Received: from pmg3.iro.umontreal.ca (localhost [127.0.0.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id B1D7E442386; Wed, 3 Sep 2025 12:10:48 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1756915847; bh=SUcQePGmeHCu/WKS3/JshufknJE7fwotww7qDUGYGro=; h=From:To:Cc:Subject:In-Reply-To:Date:From; b=mAGl66lS3OBF4EKW9BKFBr+HEHGlGgeoJ5oKeRu0YC1q2Y5rfIOwlIJ+gD7zyXxWn sK5TRkY6Cw5EjKrw3wp1iKAn44hT5PlGp13vHM+5dQjfZwKFTxKpH7NjSFWFDRVNJ0 skTcbmj2wsDljPR4H+i09gv+ZYvSYHMJO2VcMLL9hkKxsG6+5ywsfmG8wctVj+TTza DEkC0LmH6U4uoD4csK/W6Ki7vRVSmc0aQcprzGGteeg7c5rxJS+kvTcP5EGqMEnkaU SBFDpzp7kMwf9fvQltPyeCEv2uKaHENIqBUy5apCLn8eX9WYbaT0/N7FHZCURextu4 i+8FZb4z/tBQA== Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg3.iro.umontreal.ca (Proxmox) with ESMTP id 34E2A442382; Wed, 3 Sep 2025 12:10:47 -0400 (EDT) Received: from pastel (69-165-161-194.dsl.teksavvy.com [69.165.161.194]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id 14A5212006C; Wed, 3 Sep 2025 12:10:47 -0400 (EDT) From: Stefan Monnier To: Dongjin Kim Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: dts: rockchip: Change ethernet TXD timing delay value In-Reply-To: Message-ID: Date: Wed, 03 Sep 2025 12:10:46 -0400 User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-SPAM-INFO: Spam detection results: 0 ALL_TRUSTED -1 Passed through trusted hosts only via SMTP AWL -0.286 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DKIM_SIGNED 0.1 Message has a DKIM or DK signature, not necessarily valid DKIM_VALID -0.1 Message has at least one valid DKIM or DK signature DKIM_VALID_AU -0.1 Message has a valid DKIM or DK signature from author's domain DKIM_VALID_EF -0.1 Message has a valid DKIM or DK signature from envelope-from domain X-SPAM-LEVEL: Dongjin Kim wrote: > On Tue, Aug 19, 2025 at 06:03:47PM +0200, Andrew Lunn wrote: > > On Tue, Aug 19, 2025 at 01:50:17PM +0900, Dongjin Kim wrote: > > > Very poor network performance is observed on the ODROID-M1 Board > > > (REV 1.0 20220613) when running iperf3 (under 200Mbits/sec), and > > > this problem can be resolved after changing the value of TXD > > > timing to 0x35 from 0x4f. > > > > How did you decide on 0x35? > > > > ~/linux/arch/arm64$ grep -hr "tx_delay = " | sort | uniq -c > > 4 tx_delay = <0x10>; > > 1 tx_delay = <0x1a>; > > 1 tx_delay = <0x21>; > > 2 tx_delay = <0x22>; > > 4 tx_delay = <0x24>; > > 2 tx_delay = <0x26>; > > 14 tx_delay = <0x28>; > > 1 tx_delay = <0x2a>; > > 6 tx_delay = <0x30>; > > 1 tx_delay = <0x3a>; > > 3 tx_delay = <0x3c>; > > 2 tx_delay = <0x42>; > > 5 tx_delay = <0x43>; > > 2 tx_delay = <0x44>; > > 1 tx_delay = <0x46>; > > 6 tx_delay = <0x4f>; > > > > The numbers are all over the place, but it is clear that 0x28 is the > > most popular for some reason. But since this delay values are magic, > > i've no idea why. > > > > Andrew > I do have more numbers in the Rockchip BSP kernel, and 0x35 is from > one of them that shows less retry counts when testing 'iperf3' while > testing with the batch of ODROID-M1. :) FWIW, I had trouble with my Odroid-M1 whose outgoing ethernet bandwidth seemed to be limited to an average around 100kB/s, when I bumped into this thread. I applied the patch and I can now download from that Odroid at >80MB/s. So: Tested-by: Stefan Monnier Haven't tried the `rgmii-id` patch yet. Stefan