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 D551518C933 for ; Wed, 30 Jul 2025 01:51:47 +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=1753840307; cv=none; b=eqJzGUsmXgcMiBMRdSS6c2xDNYAHjIf/xbp9pQiUfU+VpSVUHk3Q1isUpg0oHHtKcmu/gAummzfGepWqWrDswR52QdZz/5KK8SvmR6dwktLocfkbIG2gjMZM5oOufpivaGeMhtpHm3C3++OYjdZbAWnCRGQBTCPhmgv0q8Q7FDw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753840307; c=relaxed/simple; bh=9HtHkWm6oII2ugGm/Moxtwt6YQVO4r1lJgDoKI68LxA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ILZMOmzTaPkgKcx5B7qi13dAdGfk1oQX5yahuUojAZXE984TSN5+BzqM8Xq9jtAl43ICA6y6EP19jMuAwnFzZGYY+frKfKczYBPjQDXa6cItRB3j1nM1vwL4u+uFmCQZycBztHu6Bmtzf9l1NAMomhRKFpBMojnAIlp5zJ8GfWs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nzykC+XO; 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="nzykC+XO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA632C4CEF4; Wed, 30 Jul 2025 01:51:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753840307; bh=9HtHkWm6oII2ugGm/Moxtwt6YQVO4r1lJgDoKI68LxA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=nzykC+XOO5rqiwCzELyqP3kpawzzt+5KH8oHFAKznqjQ9uQSBrotKDMYiQzIppRtP W0J+OcPwxOc+7CMaqz8AytXq2JegaBJopxNWYjAQpQOu6S9T0pqEYzl5r7z+FPlEpQ DYz5ZSHLe46xjJ6zdv/Tkte/rFJ/0AyevkLAxOVOBtOn7YJ5n6uxLMiyftGAh0hiUT 1KcB7Z8Lf8dyYiDvfudSorOPe/EfK6z49kNu8T44ZuVIoDfmtGYRWVAboKLPuk2dWW exgQrNgld0QW/pwhIrl1uV3SFmkieyV+tP2bpwR5F5BxqFahpdSoWxB4lL5c3D1za6 CxFXd7yZ0Z33A== Date: Tue, 29 Jul 2025 18:51:46 -0700 From: Jakub Kicinski To: Vadim Fedorenko Cc: Andrew Lunn , Michael Chan , Pavan Chebbi , Tariq Toukan , Gal Pressman , intel-wired-lan@lists.osuosl.org, Donald Hunter , Paolo Abeni , Simon Horman , netdev@vger.kernel.org Subject: Re: [RFC PATCH] ethtool: add FEC bins histogramm report Message-ID: <20250729185146.513504e0@kernel.org> In-Reply-To: <424e38be-127d-49d8-98bf-1b4a2075d710@linux.dev> References: <20250729102354.771859-1-vadfed@meta.com> <982c780a-1ff1-4d79-9104-c61605c7e802@lunn.ch> <1a7f0aa0-47ae-4936-9e55-576cdf71f4cc@linux.dev> <9c1c8db9-b283-4097-bb3f-db4a295de2a5@lunn.ch> <4270ff14-06cd-4a78-afe7-1aa5f254ebb6@linux.dev> <424e38be-127d-49d8-98bf-1b4a2075d710@linux.dev> 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-Transfer-Encoding: 7bit On Tue, 29 Jul 2025 19:07:59 +0100 Vadim Fedorenko wrote: > On 29/07/2025 18:31, Andrew Lunn wrote: > >> The only one bin will have negative value is the one to signal the end > >> of the list of the bins, which is not actually put into netlink message. > >> It actually better to change spec to have unsigned values, I believe. > > > > Can any of these NICs send runt packets? Can any send packets without > > an ethernet header and FCS? > > > > Seems to me, the bin (0,0) is meaningless, so can could be considered > > the end marker. You then have unsigned everywhere, keeping it KISS. > > I had to revisit the 802.3df-2024, and it looks like you are right: > "FEC_codeword_error_bin_i, where i=1 to 15, are optional 32-bit > counters. While align_status is true, for each codeword received with > exactly i correctable 10-bit symbols" > > That means bin (0,0) doesn't exist according to standard, so we can use > it as a marker even though some vendors provide this bin as part of > histogram. IDK, 0,0 means all symbols were completely correct. It may be useful for calculating bit error rate? A workaround for having the {-1, -1} sentinel could also be to skip the first entry: if (i && !ranges[i].low && !ranges[i].high) break;