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[2620:137:e000::1:20]) by mx.google.com with ESMTP id h20-20020a17090aa89400b00226987508d4si1429938pjq.18.2023.01.19.21.24.46; Thu, 19 Jan 2023 21:24:51 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b="XJK/TUlq"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230325AbjATFHJ (ORCPT + 47 others); Fri, 20 Jan 2023 00:07:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230290AbjATFGn (ORCPT ); Fri, 20 Jan 2023 00:06:43 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0E2985350; Thu, 19 Jan 2023 20:54:24 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D5B87B826FD; Thu, 19 Jan 2023 19:04:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35BDBC433EF; Thu, 19 Jan 2023 19:04:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674155062; bh=d2g00Jw6tz6BD9hWtgN3/3p+tv5fhKJDDTMQdPfD77w=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XJK/TUlq4tP+RkiqqZMUb2dnclna7fks8twJ14kwfW9eTsO4vDwjRbtTryPOG8NG8 6BrTOMalyK+BKkySa3GoZHZIbrX3hy5hTYi5+Fb7knfdUsbdBcuQGxQIu0OIkgXMZS wVRNy7K7N1sSZDuaq2Qtz6uqxPp5Zewc792MxH0ruNWxOjNrT4zD/RLdXGEgD79MuT dNU7v5aJ3zc+SjEwPNoZMJhwejz7A9JwwoIB+gP2nH9IACxwdbd8Hde/YBGF0aqgdd 0puiEQF0ONcQkenMGqssL14EtRKODOdmAHV/oaw0BbF4nZ9PgpRvP0DBbhMVycxFZT FMg5Evctwh7fw== Date: Thu, 19 Jan 2023 11:04:21 -0800 From: Jakub Kicinski To: Breno Leitao Cc: netdev@vger.kernel.org, leit@fb.com, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, sa+renesas@sang-engineering.com, linux-kernel@vger.kernel.org, Michael van der Westhuizen Subject: Re: [RFC PATCH v2] netpoll: Remove 4s sleep during carrier detection Message-ID: <20230119110421.3efc0f6b@kernel.org> In-Reply-To: <20230119180008.2156048-1-leitao@debian.org> References: <20230119164448.1348272-1-leitao@debian.org> <20230119180008.2156048-1-leitao@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 19 Jan 2023 10:00:08 -0800 Breno Leitao wrote: > This patch proposes to remove the msleep(4s) during netpoll_setup() if > the carrier appears instantly. > > Modern NICs do not seem to have this bouncing problem anymore, and this > sleep slows down the machine boot unnecessarily We should mention in the message that the wait is counter-productive on servers which have BMC communicating over NC-SI via the same NIC as gets used for netconsole. BMC will keep the PHY up, hence the carrier appearing instantly. We could add a smaller delay, but really having instant carrier and then loosing it seems like a driver bug, so let's try to rip the band aid off and ask for forgiveness instead. Few extra process rules: - don't repost another version within 24h, - keep a changelog under --- - add tree name to the tag - [PATCH net-next] Also, I'd just go for PATCH, no need to RFC this. If someone wants to object they can object to a PATCH.