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 9B57C1E0DA6; Tue, 8 Oct 2024 18:11:00 +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=1728411060; cv=none; b=qO5e8NUHQx2kSOS1I0BbhsyVxaetczF8D3HTAK0xDDBQIXpE98KELMecnS8r28FS4YAxmgmkG30ndotyGqR3MoG1ZlmWmgwxdkvPSeCqBQWjJhmPnOgzh2yiCLrDhYNlqcQzFOIEQE5d74T2AYEQsCNjb9fdvOwfXSo6hzKLl4E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728411060; c=relaxed/simple; bh=MbMTSNqZzM4SxVJANc6XegOhzQ6LafbFHlx1C1gQ+ks=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=rvLVQUE/RUKw3K7qgFi0ZhFOwh42wjyNeFOq7v2MhFRRcqmoq1aDDKWYJVDxFTaVoWGKSM/vArmztZMnWx9oF2WQSxyrxtnqfc9VjQM39I13PmJR/BvO9T8aTR7WopL7yCjCx30H9P9MTjmIxXY6NRsDvzPbye3HzYz28qdcHnc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mnM/2TXH; 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="mnM/2TXH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F4062C4CEC7; Tue, 8 Oct 2024 18:10:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728411060; bh=MbMTSNqZzM4SxVJANc6XegOhzQ6LafbFHlx1C1gQ+ks=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mnM/2TXH+aWz/XBoQvllNsymvF3HfbOKrm+prLlYsa/S4whoOBQni3gxrP6ufY0NN MPsIzv0Hg+3zQDXnNZZdOjatXiCvEV9ST2v0XF5i5sdUvitDZRIo8g/EMiC1Pyi0v0 E0QnD0v3NZM1ZABJPj7Ou7FM1qzeZFfErGZI3T3HhDmVUwztPX5ErXBVfu/s3lGENR qlFXlXWyXiF1tYV8BmTJKNqQ0B48Jk3oumwzAJ6SxSR0o8d6Fp8lRwyXXCSFKpZINA MxcqcvGW0s/IZb5mn+QL0SkGYZUvgMoQTRfSpCZuAZcCa8OAM6gkZCSBIRFV/79nDF ushYH98ZAczSA== Date: Tue, 8 Oct 2024 11:10:58 -0700 From: Jakub Kicinski To: Taehee Yoo Cc: Andrew Lunn , Michael Chan , davem@davemloft.net, pabeni@redhat.com, edumazet@google.com, almasrymina@google.com, netdev@vger.kernel.org, linux-doc@vger.kernel.org, donald.hunter@gmail.com, corbet@lwn.net, kory.maincent@bootlin.com, maxime.chevallier@bootlin.com, danieller@nvidia.com, hengqi@linux.alibaba.com, ecree.xilinx@gmail.com, przemyslaw.kitszel@intel.com, hkallweit1@gmail.com, ahmed.zaki@intel.com, paul.greenwalt@intel.com, rrameshbabu@nvidia.com, idosch@nvidia.com, asml.silence@gmail.com, kaiyuanz@google.com, willemb@google.com, aleksander.lobakin@intel.com, dw@davidwei.uk, sridhar.samudrala@intel.com, bcreeley@amd.com Subject: Re: [PATCH net-next v3 1/7] bnxt_en: add support for rx-copybreak ethtool command Message-ID: <20241008111058.6477e60c@kernel.org> In-Reply-To: References: <20241003160620.1521626-1-ap420073@gmail.com> <20241003160620.1521626-2-ap420073@gmail.com> 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 Sat, 5 Oct 2024 15:29:54 +0900 Taehee Yoo wrote: > > > I think a single value of 0 that means disable RX copybreak is more > > > clear and intuitive. Also, I think we can allow 64 to be a valid > > > value. > > > > > > So, 0 means to disable. 1 to 63 are -EINVAL and 64 to 1024 are valid. Thanks. > > > > Please spend a little time and see what other drivers do. Ideally we > > want one consistent behaviour for all drivers that allow copybreak to > > be disabled. > > There is no specific disable value in other drivers. > But some other drivers have min/max rx-copybreak value. > If rx-copybreak is low enough, it will not be worked. > So, min value has been working as a disable value actually. > > I think Andrew's point makes sense. > So I would like to change min value from 65 to 64, not add a disable value. Where does the min value of 64 come from? Ethernet min frame length? IIUC the copybreak threshold is purely a SW feature, after this series. If someone sets the copybreak value to, say 13 it will simply never engage but it's not really an invalid setting, IMHO. Similarly setting it to 0 makes intuitive sense (that's how e1000e works, AFAICT).