From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1C231217F31; Sat, 28 Feb 2026 00:24:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772238297; cv=none; b=nMs3Nmmma1FyAHuLUQGfg1jurVlZ+H6+xPert37fi7TVZWQnDl/iq/yierZ3Y7WKfYKka+pTDwydJ5b/iJLJ6SIFtJZ7jaRKIZ2YMABBgP0bbqyFctFqSjrfJaioMWGQWdwmFlWnrzqhUKpmiYbgAA5K/YLIe0Z7I/DG86rp6Ic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772238297; c=relaxed/simple; bh=NRLEQogbdfMsW/1W581hPUAygif/9fq5x4hpso8U3bg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=K4OU8hEMpg2wZolQiwIRFmWyvdLe1rBLsuGY+vpbo+HXomhkV84uqLVGXB0iI7CdAt6lkSKjxZJ8hvJfPBThjp6luuGM8uSyHtvbmfrqMOtRm9QX/mj+5+IPtf4RI2Jqm2NyVsZAI1LbOENN9HdhZaecRgnIG3HG/tWxdzcHymY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Hou5AiKf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hou5AiKf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 390D5C116C6; Sat, 28 Feb 2026 00:24:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772238296; bh=NRLEQogbdfMsW/1W581hPUAygif/9fq5x4hpso8U3bg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Hou5AiKfFwR/PPaHk73nZmnePlvIzv65arTZ4gwVJDQhNttR1rM8bsxiFPbfsJuZT cKGi6p5+ofabg9dKQELP0e4CEL2mJAAXUoWErEje2kTIUIhG/S9R5h5GHn0UktP+wK pQGHF2U5V4RVKtkyrY5l2Qb80hsxjeS5ENEF0yU6pEI6gefUHmf6SNLQzR6fmxFSe+ +F7prqkC0rqvBMudx/vaBSpTyg7S/IYczYOrE/Sdk6B/7UetSdcfV7fNkWLv5l/4a8 9Xan6BFfq8FWs1vdmEZW6Rln4j/Fy8o3o8Ahq8evusGC0IEWAudrZ/ZouelDFT91c5 MN8atYr8TmXdQ== Date: Fri, 27 Feb 2026 16:24:55 -0800 From: Jakub Kicinski To: Andrew Lunn Cc: Ioana Ciornei , netdev@vger.kernel.org, Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Shuah Khan , Simon Horman , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH net-next 5/5] selftests: drivers: hw: add tests for the ethtool standard counters Message-ID: <20260227162455.6272f87a@kernel.org> In-Reply-To: References: <20260225150648.1542206-1-ioana.ciornei@nxp.com> <20260225150648.1542206-6-ioana.ciornei@nxp.com> <77f3e4e8-430e-4ae1-aa1f-8f70b4d8d3da@lunn.ch> <031c7375-0407-476a-92eb-0f894ec820f1@lunn.ch> <20260226182511.0d33f9d1@kernel.org> 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-Transfer-Encoding: 7bit On Fri, 27 Feb 2026 15:17:02 +0100 Andrew Lunn wrote: > On Fri, Feb 27, 2026 at 09:34:28AM +0200, Ioana Ciornei wrote: > > On Thu, Feb 26, 2026 at 06:25:11PM -0800, Jakub Kicinski wrote: > > > FWIW the expectation is that the test should be able to run even on > > > systems / boards with a single interface. So the control traffic > > > (communicating with the traffic generator) will run over the same > > > interface as the test. 1% error is unachievable. I'd only check the > > > lower bound, and use some sanity value for the upper bound (2^30 ?) > > > if at all > > > > Really? I didn't know of that expectation at all. > > > > I did take ethtool_rmon.sh as an example and that selftest as well > > takes NUM_NETIFS=2 and does check for both a lower bound and upper bound > > that takes into account a 1% deviance from the target. > > > > How would the test even work with only a single interface? > > Just to add to this, for the 1% i was referring to counters for > collisions. If the control traffic is causing collisions the system it > just as wrongly configured as generated traffic causing collisions. > > For 'everyday' systems, i doubt Half Duplex is ever used, but > automotive with a T1 PHY might. So we might need to review this 1% > once somebody runs this test on such a system. Right, right, errors and exceptions are probably fine. I was referring to checking overall byte / packet counters with 1% tolerance. Sorry if I misread the discussion or the patch.