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 E5E8BC7EE2F for ; Sun, 26 Feb 2023 15:04:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230367AbjBZPEG (ORCPT ); Sun, 26 Feb 2023 10:04:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231726AbjBZPDk (ORCPT ); Sun, 26 Feb 2023 10:03:40 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B89B51F4AF; Sun, 26 Feb 2023 06:54:23 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 0FB6D60C3D; Sun, 26 Feb 2023 14:52:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 53E4DC433D2; Sun, 26 Feb 2023 14:52:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677423163; bh=4mc+jEkALuG+p/mOYzT2iFSpeyPvYx+oc3U5EmxsRcY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fHhdVrL2qIBj6bnB1kzPSbZYBGSOmFyMoRbhIRjMmXyjmx3XBUvxcZOQuI4EFu410 G3tyk88ugMTn06RnMX8UfTbcMQJLDWi0PZ81z41+LU1UhT0M2LV8DH91NPDMXN8452 gd019nsUmVrWiNt6vu7TnNzBd+VEbsD6DPITOpINecMwfEImV8pD2D6/c3qJ2FBCHk 7cdrfTW90BilJbRxhfpOluv4P2Z3cs39YNVxLOtM4JNe1eM8XGm9eqNcThxtmNU3yq yhFmz5p4TNlO/ZFqunOjGKgfm9jqCQr9ct77X486TV+qyalT3Sq4RfupwDo3SHpzGt HIX+rLDt1CTug== 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 4.19 09/13] netpoll: Remove 4s sleep during carrier detection Date: Sun, 26 Feb 2023 09:52:11 -0500 Message-Id: <20230226145217.829485-9-sashal@kernel.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230226145217.829485-1-sashal@kernel.org> References: <20230226145217.829485-1-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 41e32a958d08d..87a1b7e74a65c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -675,7 +675,7 @@ 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); @@ -687,7 +687,6 @@ 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)) { @@ -697,15 +696,6 @@ 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