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 77DFFC64ED6 for ; Sun, 26 Feb 2023 15:15:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231835AbjBZPPi (ORCPT ); Sun, 26 Feb 2023 10:15:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232167AbjBZPO6 (ORCPT ); Sun, 26 Feb 2023 10:14:58 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BC4B1C306; Sun, 26 Feb 2023 07:05:43 -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 0B1C8B80C01; Sun, 26 Feb 2023 14:53:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1704C433D2; Sun, 26 Feb 2023 14:53:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677423196; bh=Fj/4uNQqHMgEfrsqJTR7NelhlItSAiXEdJdKCbd07aY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=peY7y+hmJkNaAgKyqSCR3GUVHPoiR/LcY5m6PvSmA6wbVk6biLlcHV62SiB/L0KMK Hgi9cXxapnWNswaxVP1WAMYVq2QXGw6b07pSaFjMfvaBCJLe/zc+7CWspfKfJ/s82q 8lOD/lsqUhqzoCEHCGBoXY/m9EaJxxtWYAbQqbIjFusIfc1wZMspsHtJF2u0HAWulH xa0ssx0xZKYj9s2ClnxNxda2BpFUg0f9srpXTwEWzFQ2GHPnthzRxL6M0JjwoAjLvC oUf79bmZwIfD8V91E4/OXadNRw8ocxm8xDVEobIz74bGR6TkEhYJ9bVwE4HfId9cwI bhc4F0LuBFfzw== 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 4.14 08/11] netpoll: Remove 4s sleep during carrier detection Date: Sun, 26 Feb 2023 09:52:50 -0500 Message-Id: <20230226145255.829660-8-sashal@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230226145255.829660-1-sashal@kernel.org> References: <20230226145255.829660-1-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: linux-kernel@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 09a8dec1160a5..c71f20ba9109c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -698,7 +698,7 @@ 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); @@ -710,7 +710,6 @@ 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)) { @@ -720,15 +719,6 @@ 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