diff options
Diffstat (limited to 'target/linux/generic/pending-4.9/190-5-5-e1000e-Avoid-receiver-overrun-interrupt-bursts.patch')
| -rw-r--r-- | target/linux/generic/pending-4.9/190-5-5-e1000e-Avoid-receiver-overrun-interrupt-bursts.patch | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/target/linux/generic/pending-4.9/190-5-5-e1000e-Avoid-receiver-overrun-interrupt-bursts.patch b/target/linux/generic/pending-4.9/190-5-5-e1000e-Avoid-receiver-overrun-interrupt-bursts.patch new file mode 100644 index 0000000000..b42fed293d --- /dev/null +++ b/target/linux/generic/pending-4.9/190-5-5-e1000e-Avoid-receiver-overrun-interrupt-bursts.patch @@ -0,0 +1,109 @@ +From patchwork Fri Jul 21 18:36:27 2017 +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: 7bit +Subject: [5/5] e1000e: Avoid receiver overrun interrupt bursts +From: Benjamin Poirier <bpoirier@suse.com> +X-Patchwork-Id: 9857493 +Message-Id: <20170721183627.13373-5-bpoirier@suse.com> +To: Jeff Kirsher <jeffrey.t.kirsher@intel.com> +Cc: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>, + intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, + linux-kernel@vger.kernel.org +Date: Fri, 21 Jul 2017 11:36:27 -0700 + +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 <lsorense@csclub.uwaterloo.ca> +Fixes: 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt") +Signed-off-by: Benjamin Poirier <bpoirier@suse.com> +--- + drivers/net/ethernet/intel/e1000e/defines.h | 1 + + drivers/net/ethernet/intel/e1000e/netdev.c | 33 +++++++++++++++++++++++------ + 2 files changed, 27 insertions(+), 7 deletions(-) + +--- 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 */ +--- a/drivers/net/ethernet/intel/e1000e/netdev.c ++++ b/drivers/net/ethernet/intel/e1000e/netdev.c +@@ -1905,12 +1905,30 @@ static irqreturn_t e1000_msix_other(int + struct net_device *netdev = data; + struct e1000_adapter *adapter = netdev_priv(netdev); + struct e1000_hw *hw = &adapter->hw; ++ u32 icr; ++ bool enable = true; + +- hw->mac.get_link_status = 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); ++ } ++ } + +- /* 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); + } + +@@ -2683,7 +2701,8 @@ static int e1000e_poll(struct napi_struc + 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); + } +@@ -4178,7 +4197,7 @@ static void e1000e_trigger_lsc(struct e1 + 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); + } |