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Miller" , Jakub Kicinski , Jacob Keller , roopa@nvidia.com, mlxsw References: <20210113121222.733517-1-jiri@resnulli.us> <9b940a66-8c91-34c1-e64e-42b92bf403a8@gmail.com> From: David Ahern Message-ID: <5ee0f841-2474-ef27-ac5d-7686d40bc18f@gmail.com> Date: Mon, 18 Jan 2021 19:39:47 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 1/18/21 4:40 PM, Edwin Peer wrote: > On Mon, Jan 18, 2021 at 2:57 PM David Ahern wrote: > >> On 1/18/21 11:01 AM, Edwin Peer wrote: >>> I'm facing a similar issue with NIC firmware that isn't yet ready by >>> device open time, but have been resisting the urge to lie to the stack >> >> why not have the ndo_open return -EBUSY or -EAGAIN to tell S/W to try >> again 'later'? > > Indeed, this is what we ended up doing, although we still need to > confirm Network Manager, systemd and whatever else our customers might > use do the necessary to satisfy the user requirement to handle the > delayed init. I am not surprised about the issue - boot times have been improved and devices have gotten more complicated. And I was wondering how network managers (add ifupdown{2} to that list) would handle an EAGAIN. You could have an event sent -- e.g., IFLA_EVENT_FW_READY -- to allow managers to avoid polling. Redundant for multiple netdev's per device, but makes it event driven. > > Only reason I piped up is that this line card thing seems to introduce > a similar issue. Seems reasonable.