netdev - [PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  8 Feb 2018 15:47:12 +0900
From:   Benjamin Poirier <bpoirier@...e.com>
To:     Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Cc:     Alexander Duyck <alexander.duyck@...il.com>,
        intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.

We keep the fix for the first part of the problem (1) described in the log
of that commit, that is to read ICR in the other interrupt handler. We
remove the fix for the second part of the problem (2), Other interrupt
throttling.

Bursts of "Other" interrupts may once again occur during rxo (receive
overflow) traffic conditions. This is deemed acceptable in the interest of
avoiding unforeseen fallout from changes that are not strictly necessary.
As discussed, the e1000e driver should be in "maintenance mode".

Link: https://www.spinics.net/lists/netdev/msg480675.html
Signed-off-by: Benjamin Poirier <bpoirier@...e.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 153ad406c65e..3b36efa6228d 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1915,21 +1915,10 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	struct e1000_hw *hw = &adapter->hw;
 	u32 icr;
-	bool enable = true;
 
 	icr = er32(ICR);
 	ew32(ICR, E1000_ICR_OTHER);
 
-	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;
@@ -1938,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 			mod_timer(&adapter->watchdog_timer, jiffies + 1);
 	}
 
-	if (enable && !test_bit(__E1000_DOWN, &adapter->state))
+	if (!test_bit(__E1000_DOWN, &adapter->state))
 		ew32(IMS, E1000_IMS_OTHER);
 
 	return IRQ_HANDLED;
@@ -2708,8 +2697,7 @@ 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 |
-				     E1000_IMS_OTHER);
+				ew32(IMS, adapter->rx_ring->ims_val);
 			else
 				e1000_irq_enable(adapter);
 		}
-- 
2.16.1