From patchwork Mon Nov 9 23:50:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Poirier X-Patchwork-Id: 542066 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id AF0261401DE for ; Tue, 10 Nov 2015 10:51:52 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752200AbbKIXve (ORCPT ); Mon, 9 Nov 2015 18:51:34 -0500 Received: from mx2.suse.de ([195.135.220.15]:57006 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752128AbbKIXvc (ORCPT ); Mon, 9 Nov 2015 18:51:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 1E7FEAC0B; Mon, 9 Nov 2015 23:51:11 +0000 (UTC) From: Benjamin Poirier To: Jeff Kirsher Cc: Alexander Duyck , Frank Steiner , Jesse Brandeburg , Shannon Nelson , Carolyn Wyborny , Don Skidmore , Matthew Vick , John Ronciak , Mitch Williams , intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 4/4] e1000e: Fix msi-x interrupt automask Date: Mon, 9 Nov 2015 15:50:21 -0800 Message-Id: <1447113021-1611-5-git-send-email-bpoirier@suse.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1447113021-1611-1-git-send-email-bpoirier@suse.com> References: <1447113021-1611-1-git-send-email-bpoirier@suse.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since the introduction of 82574 support in e1000e, the driver has worked on the assumption that msi-x interrupt generation is automatically disabled after each irq. As it turns out, this is not the case. Currently, rx interrupts can fire multiple times before and during napi processing. This can be a problem for users because frames that arrive in a certain window (after adapter->clean_rx() but before napi_complete_done() has cleared NAPI_STATE_SCHED) generate an interrupt which does not lead to napi_schedule(). These frames sit in the rx queue until another frame arrives (a tcp retransmit for example). While the EIAC and CTRL_EXT registers are properly configured for irq automask, the modification of IAM in e1000_configure_msix() is what prevents automask from working as intended. This patch removes that erroneous write and fixes interrupt rearming for tx interrupts. It also clears IAME from CTRL_EXT. This is not strictly necessary for operation of the driver but it is to avoid disruption from potential programs that access the registers directly, like `ethregs -c`. Reported-by: Frank Steiner Signed-off-by: Benjamin Poirier --- drivers/net/ethernet/intel/e1000e/netdev.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index ed7cc8e..2a22ed7 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -1931,6 +1931,9 @@ static irqreturn_t e1000_intr_msix_tx(int __always_unused irq, void *data) /* Ring was not completely cleaned, so fire another interrupt */ ew32(ICS, tx_ring->ims_val); + if (!test_bit(__E1000_DOWN, &adapter->state)) + ew32(IMS, adapter->tx_ring->ims_val); + return IRQ_HANDLED; } @@ -2018,12 +2021,8 @@ static void e1000_configure_msix(struct e1000_adapter *adapter) ew32(IVAR, ivar); /* enable MSI-X PBA support */ - ctrl_ext = er32(CTRL_EXT); - ctrl_ext |= E1000_CTRL_EXT_PBA_CLR; - - /* Auto-Mask Other interrupts upon ICR read */ - ew32(IAM, ~E1000_EIAC_MASK_82574 | E1000_IMS_OTHER); - ctrl_ext |= E1000_CTRL_EXT_EIAME; + ctrl_ext = er32(CTRL_EXT) & ~E1000_CTRL_EXT_IAME; + ctrl_ext |= E1000_CTRL_EXT_PBA_CLR | E1000_CTRL_EXT_EIAME; ew32(CTRL_EXT, ctrl_ext); e1e_flush(); }