From patchwork Wed Sep 11 16:49:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirsher, Jeffrey T" X-Patchwork-Id: 1161138 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46T7DS3hmkz9sNk for ; Thu, 12 Sep 2019 02:50:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729303AbfIKQt6 (ORCPT ); Wed, 11 Sep 2019 12:49:58 -0400 Received: from mga14.intel.com ([192.55.52.115]:31944 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728794AbfIKQt6 (ORCPT ); Wed, 11 Sep 2019 12:49:58 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2019 09:49:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,492,1559545200"; d="scan'208";a="179078816" Received: from jtkirshe-desk1.jf.intel.com ([134.134.177.96]) by orsmga008.jf.intel.com with ESMTP; 11 Sep 2019 09:49:57 -0700 From: Jeff Kirsher To: davem@davemloft.net Cc: Alexander Duyck , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, stable@vger.kernel.org, Gregg Leventhal , Andrew Bowers , Jeff Kirsher Subject: [net 1/2] ixgbe: Prevent u8 wrapping of ITR value to something less than 10us Date: Wed, 11 Sep 2019 09:49:54 -0700 Message-Id: <20190911164955.10644-2-jeffrey.t.kirsher@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190911164955.10644-1-jeffrey.t.kirsher@intel.com> References: <20190911164955.10644-1-jeffrey.t.kirsher@intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Alexander Duyck There were a couple cases where the ITR value generated via the adaptive ITR scheme could exceed 126. This resulted in the value becoming either 0 or something less than 10. Switching back and forth between a value less than 10 and a value greater than 10 can cause issues as certain hardware features such as RSC to not function well when the ITR value has dropped that low. CC: stable@vger.kernel.org Fixes: b4ded8327fea ("ixgbe: Update adaptive ITR algorithm") Reported-by: Gregg Leventhal Signed-off-by: Alexander Duyck Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 7882148abb43..77ca9005dc41 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -2621,7 +2621,7 @@ static void ixgbe_update_itr(struct ixgbe_q_vector *q_vector, /* 16K ints/sec to 9.2K ints/sec */ avg_wire_size *= 15; avg_wire_size += 11452; - } else if (avg_wire_size <= 1980) { + } else if (avg_wire_size < 1968) { /* 9.2K ints/sec to 8K ints/sec */ avg_wire_size *= 5; avg_wire_size += 22420; @@ -2654,6 +2654,8 @@ static void ixgbe_update_itr(struct ixgbe_q_vector *q_vector, case IXGBE_LINK_SPEED_2_5GB_FULL: case IXGBE_LINK_SPEED_1GB_FULL: case IXGBE_LINK_SPEED_10_FULL: + if (avg_wire_size > 8064) + avg_wire_size = 8064; itr += DIV_ROUND_UP(avg_wire_size, IXGBE_ITR_ADAPTIVE_MIN_INC * 64) * IXGBE_ITR_ADAPTIVE_MIN_INC;