From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next 9/9] e1000e: Fix msi-x interrupt automask Date: Mon, 14 Dec 2015 21:38:44 -0800 Message-ID: <1450157924-58901-10-git-send-email-jeffrey.t.kirsher@intel.com> References: <1450157924-58901-1-git-send-email-jeffrey.t.kirsher@intel.com> Cc: Benjamin Poirier , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga09.intel.com ([134.134.136.24]:59689 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751588AbbLOFiu (ORCPT ); Tue, 15 Dec 2015 00:38:50 -0500 In-Reply-To: <1450157924-58901-1-git-send-email-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Benjamin Poirier 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 Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- 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 d59c0bc..c71ba1b 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; } @@ -2020,12 +2023,8 @@ 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(); } -- 2.5.0