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 53DD51862A for ; Thu, 28 Aug 2025 20:09:51 +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=1756411792; cv=none; b=kc3/o43dtp7KH9Wnh+jnKoHf+y80OGkgADYt9VnX+Lc4LjAXSDCn7+2DEpRLoHY1AH/2fuzth+tzWjG7nigzNzQoP4pTd382Yy0PXseg2SXfBREXCsDTv2LUN+SKx/4v0QAvz2N0FLzQa3kR45agyIxaERIZ7Tnkliu5chIx3Os= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756411792; c=relaxed/simple; bh=WVVhSFnEfuQY5vGS7w9O7aus+94H8CFCh01HdLD/b8k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Hzr5QbWls4Cft+6X3kf/jQOkLB2ByNp5FBatXVO/88/Iepd0iipax21V22oRa7jlR8WXYuq1qlZKHW9ZU8f92EgrN6Sqt12Sn7mAuntGyEwiPtCFM/M6/UPEyGGtkufi+xUg0dY7eS+OAlX+wTHsJ8fjae/kCe4mIAz5rnJcLi8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=frV3LaKH; 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="frV3LaKH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC0A1C4CEEB; Thu, 28 Aug 2025 20:09:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756411791; bh=WVVhSFnEfuQY5vGS7w9O7aus+94H8CFCh01HdLD/b8k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=frV3LaKH4cwyRA7Frh+pDKtNYvZ8QCIRNCw3tW5pVLJ9uvghfY0hrW3T/FF+hSPeo WzVeSvSIp2yL4u6XyM53MpbpO7MDXfVn/I/StEs0zrh+Qy677WVY1//SP7QZUsqpnM C0x5OCRMbBacsVkueMYviqj1dAFymga6L+HAEVT9mt8Ih9Z0AixEs1f5PuGQOrflLD 0uNlYNznlgaMC7mS2q1sFqJXxhlOlkb0yp67Khb+KbIL5Zy5yKtxap3T8qR6JriJQY 7JAfE6aco1JqLzp58REbnTOs3YcAcSjq0tX+wkHXJE5tf1mjoF0Teg0nU9DIBiiaDy RMzBNIx6SbUag== Date: Thu, 28 Aug 2025 13:09:50 -0700 From: Saeed Mahameed To: Jakub Kicinski Cc: "David S. Miller" , Paolo Abeni , Eric Dumazet , Saeed Mahameed , netdev@vger.kernel.org, Tariq Toukan , Gal Pressman , Leon Romanovsky , Jiri Pirko , Simon Horman Subject: Re: [PATCH net-next V6 09/13] devlink: Add 'keep_link_up' generic devlink device param Message-ID: References: <20250709030456.1290841-1-saeed@kernel.org> <20250709030456.1290841-10-saeed@kernel.org> <20250709195801.60b3f4f2@kernel.org> <20250710152421.31901790@kernel.org> 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; format=flowed Content-Disposition: inline In-Reply-To: <20250710152421.31901790@kernel.org> On 10 Jul 15:24, Jakub Kicinski wrote: >On Wed, 9 Jul 2025 23:04:07 -0700 Saeed Mahameed wrote: >> On 09 Jul 19:58, Jakub Kicinski wrote: >> >On Tue, 8 Jul 2025 20:04:51 -0700 Saeed Mahameed wrote: >> >> Devices that support this in permanent mode will be requested to keep the >> >> port link up even when driver is not loaded, netdev carrier state won't >> >> affect the physical port link state. >> >> >> >> This is useful for when the link is needed to access onboard management >> >> such as BMC, even if the host driver isn't loaded. >> > >> >Dunno. This deserves a fuller API, and it's squarely and netdev thing. >> >Let's not add it to devlink. >> >> I don't see anything missing in the definition of this parameter >> 'keep_link_up' it is pretty much self-explanatory, for legacy reasons the >> netdev controls the underlying physical link state. But this is not >> true anymore for complex setups (multi-host, DPU, etc..). > >The policy can be more complex than "keep_link_up" >Look around the tree and search the ML archives please. > Sorry for replying late, had to work on other stuff and was waiting internally for a question I had to ask about this, only recently got the answer. I get your point, but I am not trying to implement any link policy or eth link specification tunables. For me and maybe other vendors this knob makes sense, and Important for the usecase I described. Perhaps move it to a vendor specific knob ? or rename to link_{fw/soc}_controlled? >> This is not different as BMC is sort of multi-host, and physical link >> control here is delegated to the firmware. >> >> Also do we really want netdev to expose API for permanent nic tunables ? >> I thought this is why we invented devlink to offload raw NIC underlying >> tunables. > >Are you going to add devlink params for link config? >Its one of the things that's written into the NVMe, usually.. No, the purpose of this NVM series is to setup FW boot parameters and not spec related tunables.