From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.nabladev.com (mx.nabladev.com [178.251.229.89]) (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 D1EEC248893; Thu, 15 Oct 2026 23:48:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.251.229.89 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792108087; cv=none; b=jGat3ryfvq8UJxml1lPe97P+TRGaKrKXXlbHWt7leFTcT697TxvmGQSmlJdoCJlMUgzJlos3vFIF2VZK0f7DjfZumn11v96DruVjGamhIAOMEMjrHgqH1yrCZgDOa/4tmpOOeB5vItaoMnsNydJgo4VL5vhq2qzC7pwA1rGe+7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792108087; c=relaxed/simple; bh=m27SmZZTS7JpMwtLitQ0k7tJ3ZHPI8bxno74mTETTsI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WcN0vDTPdudZtGvxJ1CWJiByj6cJ6x25RRKAzw8LiyT3CoP+WIQBPv3RiLtUbS424K/0NQebL8L1bj1LIxwrlxpOmKZ0Y2DMYUh9IZFuX210M8eAiiXYRQd6fjNgkelzlh9WcdB5L1mPgfxmp/cIIisaL61KrxaCBfRcHff1X+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nabladev.com; spf=pass smtp.mailfrom=nabladev.com; dkim=pass (2048-bit key) header.d=nabladev.com header.i=@nabladev.com header.b=dyIUXUSn; arc=none smtp.client-ip=178.251.229.89 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nabladev.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nabladev.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nabladev.com header.i=@nabladev.com header.b="dyIUXUSn" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 391B51082A1; Fri, 16 Oct 2026 01:47:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nabladev.com; s=dkim; t=1792108073; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:content-language:in-reply-to:references; bh=odgiDLhjLN5ABbzDY81bVr2SK/hEUupDPKG/mRLLcQo=; b=dyIUXUSnfbx5JPj9xwmce7sdh3eqYg1BddGhsGlr2ILCCag/yMBhihpJwgJbLUJYGrP3Tb GioP4cm+ZkZsDPh34k+mipoB1ArBzN+q4hLdPXoBPpHA8IkxrHQdGusBiBpCayvxy715kt eEBrgsNYKf0HZyEW7VjYY4Cn2ORXwN/aKtNGLk5Y0Rv2LXoeR5bjm4AV3IVh/O5xhwFxMw MsASeLBtQAFY7yc2plsz2IN5+urBPIsRtiSq3s4yd4whZsNyLUwtyWyQg+8kISuOqLZ0J7 MljKKfZInTiPmSsIQXrscENW4qoLuqyJQLA5IrlY/eKUOYiRUQNLDcVVMSY0mw== Message-ID: <83380f02-6dc7-4aaa-8987-be17fbd26d4c@nabladev.com> Date: Thu, 15 Oct 2026 23:20:52 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [net-next,PATCH v2] enetc: Increase eMDIO MDC rate to 2.5 MHz To: Wei Fang , Clark Wang , Claudiu Manoil , Vladimir Oltean Cc: "David S. Miller" , Andrew Lunn , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "imx@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" References: <20260924180607.60932-1-marex@nabladev.com> Content-Language: en-US From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 On 10/13/26 4:17 AM, Wei Fang wrote: >>>>>> Clark helped measure the MDC rate on the 95 EVK board this morning, >>>>>> and the result was 644KHz, which is consistent with the theoretical >>>>>> value. The scope's accuracy or other factors may be causing you to >>>>>> observe a rate of 558kHz. >>>>> >>>>> That 644 kHz and 558 kHz differs too much to be an equipment >>>>> miscalibration / misuse. >>>> >>>> For the sake of completeness, the MX95 B0 I have on my desk now >>>> prints this in >>>> SM: >>>> >>>> >$ clock.r >>>> ... >>>> 097: busnetcmix = on, 133333333Hz >>>> 098: enet = on, 666666666Hz >>>> 099: enetphytest200m = on, 24000000Hz >>>> 100: enetphytest500m = on, 24000000Hz >>>> 101: enetphytest667m = on, 24000000Hz >>>> 102: enetref = on, 250000000Hz >>>> 103: enettimer1 = on, 24000000Hz >>>> >>>> And the cycle time of MDC is 1.8ms , which is some 550 kHz . >>> >>> The enet clock is the source of NETC system clock, and there is a 1/2 >>> divisor inside the NETCMIX, so the NETC system clock is 333 MHz. >>> So the MDC clock should be 644 KHz, the frequency measured by Clark in >>> the attachment is indeed 644kHz. >> Is there maybe any other clock source that might feed the MDC clock on >> MX95 B0, that could explain the 558 kHz I observe ? > > I do not think so. If that's the case, then setting the divisor to 66 would not > result in a MDC clock of 2.5 MHz. Hmmm, I see. (also, I apologize for the slow response, I am completely flooded by emails, I still need a few days to get back to this topic)