From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58084C7EE31 for ; Sun, 26 Feb 2023 15:10:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231788AbjBZPKR (ORCPT ); Sun, 26 Feb 2023 10:10:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231991AbjBZPKD (ORCPT ); Sun, 26 Feb 2023 10:10:03 -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 B49AD24109; Sun, 26 Feb 2023 07:00:11 -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 0C28BB80C69; Sun, 26 Feb 2023 14:49:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A030BC433B4; Sun, 26 Feb 2023 14:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677422975; bh=i2wLzmlocFC7GteqWZlIZcLNTuNTfmUdaf499qavuK4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LPLrH4GcHwIdm5/OeMMRE5f5TFRjKvw6Bwp/XisgN3If7OC82WmHvtNXMQs/GQsj4 5yBp3ifG5E3+eTG6BL5zJ/19qaQVlnLTAh0bhr4oES2jpsPghTzX7mOuebN9CwM4Lq ixgM3F3Lp+8Z3CtI49ODth4SnXDcAyswpOiPA8OrHyHHyjgP/0aXXlx4JeMi2UcB8N 8kTS0kRZJpItJ8MPc9AeHbSaiam1TYhfCMRSRp7P5Qqbsitw4L03tyDAMmlckUaHoW 490UgXjmt4LIM2qIzz4b82MVVgL58apCQWK8agZL6eX1q+Mnl1bo2Dfef2dyIXX9c4 RADdX/G9PsL5g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Breno Leitao , Michael van der Westhuizen , Jakub Kicinski , Sasha Levin , davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, wsa+renesas@sang-engineering.com, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 19/36] netpoll: Remove 4s sleep during carrier detection Date: Sun, 26 Feb 2023 09:48:27 -0500 Message-Id: <20230226144845.827893-19-sashal@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230226144845.827893-1-sashal@kernel.org> References: <20230226144845.827893-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Breno Leitao [ Upstream commit d8afe2f8a92d2aac3df645772f6ee61b0b2fc147 ] This patch removes the msleep(4s) during netpoll_setup() if the carrier appears instantly. Here are some scenarios where this workaround is counter-productive in modern ages: 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. The link is fibre, SERDES getting sync could happen within 0.1Hz, and the carrier also appears instantly. Other than that, if a driver is reporting instant carrier and then losing it, this is probably a driver bug. Reported-by: Michael van der Westhuizen Signed-off-by: Breno Leitao Link: https://lore.kernel.org/r/20230125185230.3574681-1-leitao@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/netpoll.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/net/core/netpoll.c b/net/core/netpoll.c index edfc0f8011f88..0fc64f536db01 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -682,7 +682,7 @@ int netpoll_setup(struct netpoll *np) } if (!netif_running(ndev)) { - unsigned long atmost, atleast; + unsigned long atmost; np_info(np, "device %s not up yet, forcing it\n", np->dev_name); @@ -694,7 +694,6 @@ int netpoll_setup(struct netpoll *np) } rtnl_unlock(); - atleast = jiffies + HZ/10; atmost = jiffies + carrier_timeout * HZ; while (!netif_carrier_ok(ndev)) { if (time_after(jiffies, atmost)) { @@ -704,15 +703,6 @@ int netpoll_setup(struct netpoll *np) msleep(1); } - /* If carrier appears to come up instantly, we don't - * trust it and pause so that we don't pump all our - * queued console messages into the bitbucket. - */ - - if (time_before(jiffies, atleast)) { - np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); - msleep(4000); - } rtnl_lock(); } -- 2.39.0