Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757102AbdLVIvK (ORCPT ); Fri, 22 Dec 2017 03:51:10 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33954 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757075AbdLVIvE (ORCPT ); Fri, 22 Dec 2017 03:51:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Duyck , Andrew Bowers , Jeff Kirsher , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 43/78] i40e: Do not enable NAPI on q_vectors that have no rings Date: Fri, 22 Dec 2017 09:46:24 +0100 Message-Id: <20171222084601.766879823@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171222084556.909780563@linuxfoundation.org> References: <20171222084556.909780563@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1933 Lines: 58 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Duyck [ Upstream commit 13a8cd191a2b470cfd435b3b57dbd21aa65ff78c ] When testing the epoll w/ busy poll code I found that I could get into a state where the i40e driver had q_vectors w/ active NAPI that had no rings. This was resulting in a divide by zero error. To correct it I am updating the driver code so that we only support NAPI on q_vectors that have 1 or more rings allocated to them. Signed-off-by: Alexander Duyck Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/i40e/i40e_main.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -4201,8 +4201,12 @@ static void i40e_napi_enable_all(struct if (!vsi->netdev) return; - for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) - napi_enable(&vsi->q_vectors[q_idx]->napi); + for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) { + struct i40e_q_vector *q_vector = vsi->q_vectors[q_idx]; + + if (q_vector->rx.ring || q_vector->tx.ring) + napi_enable(&q_vector->napi); + } } /** @@ -4216,8 +4220,12 @@ static void i40e_napi_disable_all(struct if (!vsi->netdev) return; - for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) - napi_disable(&vsi->q_vectors[q_idx]->napi); + for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) { + struct i40e_q_vector *q_vector = vsi->q_vectors[q_idx]; + + if (q_vector->rx.ring || q_vector->tx.ring) + napi_disable(&q_vector->napi); + } } /**