From patchwork Thu Dec 14 15:17:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Salisbury X-Patchwork-Id: 848611 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3yyHHk4pCwz9t4B; Fri, 15 Dec 2017 02:17:54 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1ePVGg-0002I2-Nf; Thu, 14 Dec 2017 15:17:50 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1ePVGb-0002DE-HY for kernel-team@lists.ubuntu.com; Thu, 14 Dec 2017 15:17:45 +0000 Received: from 1.general.jsalisbury.us.vpn ([10.172.67.212] helo=salisbury) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1ePVGb-00040s-6v for kernel-team@lists.ubuntu.com; Thu, 14 Dec 2017 15:17:45 +0000 Received: by salisbury (Postfix, from userid 1000) id 3834D7E26CB; Thu, 14 Dec 2017 10:17:44 -0500 (EST) From: Joseph Salisbury To: kernel-team@lists.ubuntu.com Subject: [SRU][X, Z, A][PATCH 1/2] e1000e: Separate signaling for link check/link up Date: Thu, 14 Dec 2017 10:17:43 -0500 Message-Id: <657981560c26442b5947562af26e9eacba47fe16.1510153524.git.joseph.salisbury@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Benjamin Poirier BugLink: http://bugs.launchpad.net/bugs/1730550 Lennart reported the following race condition: \ e1000_watchdog_task \ e1000e_has_link \ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link /* link is up */ mac->get_link_status = false; /* interrupt */ \ e1000_msix_other hw->mac.get_link_status = true; link_active = !hw->mac.get_link_status /* link_active is false, wrongly */ This problem arises because the single flag get_link_status is used to signal two different states: link status needs checking and link status is down. Avoid the problem by using the return value of .check_for_link to signal the link status to e1000e_has_link(). Reported-by: Lennart Sorensen Signed-off-by: Benjamin Poirier Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher (cherry picked from commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013) Signed-off-by: Joseph Salisbury --- drivers/net/ethernet/intel/e1000e/mac.c | 11 ++++++++--- drivers/net/ethernet/intel/e1000e/netdev.c | 2 +- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c index e59d7c2..645ace7 100644 --- a/drivers/net/ethernet/intel/e1000e/mac.c +++ b/drivers/net/ethernet/intel/e1000e/mac.c @@ -410,6 +410,9 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw) * Checks to see of the link status of the hardware has changed. If a * change in link status has been detected, then we read the PHY registers * to get the current speed/duplex if link exists. + * + * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link + * up). **/ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) { @@ -423,7 +426,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) * Change or Rx Sequence Error interrupt. */ if (!mac->get_link_status) - return 0; + return 1; /* First we want to see if the MII Status Register reports * link. If so, then we want to get the current speed/duplex @@ -461,10 +464,12 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw) * different link partner. */ ret_val = e1000e_config_fc_after_link_up(hw); - if (ret_val) + if (ret_val) { e_dbg("Error configuring flow control\n"); + return ret_val; + } - return ret_val; + return 1; } /** diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index 9b4ec13..acc0e57 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -5006,7 +5006,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter) case e1000_media_type_copper: if (hw->mac.get_link_status) { ret_val = hw->mac.ops.check_for_link(hw); - link_active = !hw->mac.get_link_status; + link_active = ret_val > 0; } else { link_active = true; } From patchwork Thu Dec 14 15:17:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Salisbury X-Patchwork-Id: 848610 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3yyHHh4dxsz9t3m; Fri, 15 Dec 2017 02:17:52 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1ePVGe-0002FM-DF; Thu, 14 Dec 2017 15:17:48 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1ePVGb-0002DF-Kg for kernel-team@lists.ubuntu.com; Thu, 14 Dec 2017 15:17:45 +0000 Received: from 1.general.jsalisbury.us.vpn ([10.172.67.212] helo=salisbury) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1ePVGb-00040t-7O for kernel-team@lists.ubuntu.com; Thu, 14 Dec 2017 15:17:45 +0000 Received: by salisbury (Postfix, from userid 1000) id 39B857E26E4; Thu, 14 Dec 2017 10:17:44 -0500 (EST) From: Joseph Salisbury To: kernel-team@lists.ubuntu.com Subject: [SRU][X, Z, A][PATCH 2/2] e1000e: Avoid receiver overrun interrupt bursts Date: Thu, 14 Dec 2017 10:17:44 -0500 Message-Id: <04e9e0e6becd316f2ecc89d960116269c11ab8f2.1510153524.git.joseph.salisbury@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Benjamin Poirier BugLink: http://bugs.launchpad.net/bugs/1730550 When e1000e_poll() is not fast enough to keep up with incoming traffic, the adapter (when operating in msix mode) raises the Other interrupt to signal Receiver Overrun. This is a double problem because 1) at the moment e1000_msix_other() assumes that it is only called in case of Link Status Change and 2) if the condition persists, the interrupt is repeatedly raised again in quick succession. Ideally we would configure the Other interrupt to not be raised in case of receiver overrun but this doesn't seem possible on this adapter. Instead, we handle the first part of the problem by reverting to the practice of reading ICR in the other interrupt handler, like before commit 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt"). Thanks to commit 0a8047ac68e5 ("e1000e: Fix msi-x interrupt automask") which cleared IAME from CTRL_EXT, reading ICR doesn't interfere with RxQ0, TxQ0 interrupts anymore. We handle the second part of the problem by not re-enabling the Other interrupt right away when there is overrun. Instead, we wait until traffic subsides, napi polling mode is exited and interrupts are re-enabled. Reported-by: Lennart Sorensen Fixes: 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt") Signed-off-by: Benjamin Poirier Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher (cherry picked from commit 4aea7a5c5e940c1723add439f4088844cd26196d) Signed-off-by: Joseph Salisbury --- drivers/net/ethernet/intel/e1000e/defines.h | 1 + drivers/net/ethernet/intel/e1000e/netdev.c | 33 ++++++++++++++++++++++------- 2 files changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h index 0641c00..afb7ebe 100644 --- a/drivers/net/ethernet/intel/e1000e/defines.h +++ b/drivers/net/ethernet/intel/e1000e/defines.h @@ -398,6 +398,7 @@ #define E1000_ICR_LSC 0x00000004 /* Link Status Change */ #define E1000_ICR_RXSEQ 0x00000008 /* Rx sequence error */ #define E1000_ICR_RXDMT0 0x00000010 /* Rx desc min. threshold (0) */ +#define E1000_ICR_RXO 0x00000040 /* Receiver Overrun */ #define E1000_ICR_RXT0 0x00000080 /* Rx timer intr (ring 0) */ #define E1000_ICR_ECCER 0x00400000 /* Uncorrectable ECC Error */ /* If this bit asserted, the driver should claim the interrupt */ diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c index acc0e57..f873349 100644 --- a/drivers/net/ethernet/intel/e1000e/netdev.c +++ b/drivers/net/ethernet/intel/e1000e/netdev.c @@ -1905,14 +1905,30 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data) struct net_device *netdev = data; struct e1000_adapter *adapter = netdev_priv(netdev); struct e1000_hw *hw = &adapter->hw; + u32 icr; + bool enable = true; + + icr = er32(ICR); + if (icr & E1000_ICR_RXO) { + ew32(ICR, E1000_ICR_RXO); + enable = false; + /* napi poll will re-enable Other, make sure it runs */ + if (napi_schedule_prep(&adapter->napi)) { + adapter->total_rx_bytes = 0; + adapter->total_rx_packets = 0; + __napi_schedule(&adapter->napi); + } + } + if (icr & E1000_ICR_LSC) { + ew32(ICR, E1000_ICR_LSC); + hw->mac.get_link_status = true; + /* guard against interrupt when we're going down */ + if (!test_bit(__E1000_DOWN, &adapter->state)) + mod_timer(&adapter->watchdog_timer, jiffies + 1); + } - hw->mac.get_link_status = true; - - /* guard against interrupt when we're going down */ - if (!test_bit(__E1000_DOWN, &adapter->state)) { - mod_timer(&adapter->watchdog_timer, jiffies + 1); + if (enable && !test_bit(__E1000_DOWN, &adapter->state)) ew32(IMS, E1000_IMS_OTHER); - } return IRQ_HANDLED; } @@ -2683,7 +2699,8 @@ static int e1000e_poll(struct napi_struct *napi, int weight) napi_complete_done(napi, work_done); if (!test_bit(__E1000_DOWN, &adapter->state)) { if (adapter->msix_entries) - ew32(IMS, adapter->rx_ring->ims_val); + ew32(IMS, adapter->rx_ring->ims_val | + E1000_IMS_OTHER); else e1000_irq_enable(adapter); } @@ -4142,7 +4159,7 @@ static void e1000e_trigger_lsc(struct e1000_adapter *adapter) struct e1000_hw *hw = &adapter->hw; if (adapter->msix_entries) - ew32(ICS, E1000_ICS_OTHER); + ew32(ICS, E1000_ICS_LSC | E1000_ICS_OTHER); else ew32(ICS, E1000_ICS_LSC); }