From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Poirier Subject: [PATCH v2 4/4] e1000e: Fix msi-x interrupt automask Date: Fri, 30 Oct 2015 10:31:04 -0700 Message-ID: <1446226264-29660-5-git-send-email-bpoirier@suse.com> References: <1446226264-29660-1-git-send-email-bpoirier@suse.com> 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 To: Jeff Kirsher Return-path: In-Reply-To: <1446226264-29660-1-git-send-email-bpoirier@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: 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. Reported-by: Frank Steiner Signed-off-by: Benjamin Poirier --- drivers/net/ethernet/intel/e1000e/netdev.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 639fbe8..b5549d1 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -1932,6 +1932,9 @@ 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; } @@ -2020,11 +2023,7 @@ static void e1000_configure_msix(struct e1000_adapter *adapter) /* 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 |= E1000_CTRL_EXT_PBA_CLR | E1000_CTRL_EXT_EIAME; ew32(CTRL_EXT, ctrl_ext); e1e_flush(); } -- 2.6.0