e1000e: adjust PM QoS request
It has been found that devices other than 82579 (a.k.a. e1000_pch2lan)
suffer from dropped transactions on platforms with deep C-states when
jumbo frames are enabled. For example, LOMs on ICH9- and ICH10-based
platforms which recently had early-receive de-featured (for stability
reasons) suffer from this. To resolve this for all devices, when jumbo
frames are enabled set the PM QoS DMA latency request based on the size
of the receive packet buffer less one full frame.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index e386e95..46a38a4 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3242,18 +3242,23 @@
rxcsum &= ~E1000_RXCSUM_TUOFL;
ew32(RXCSUM, rxcsum);
- if (adapter->hw.mac.type == e1000_pch2lan) {
- /* With jumbo frames, excessive C-state transition
- * latencies result in dropped transactions.
- */
- if (adapter->netdev->mtu > ETH_DATA_LEN) {
+ /* With jumbo frames, excessive C-state transition latencies result
+ * in dropped transactions.
+ */
+ if (adapter->netdev->mtu > ETH_DATA_LEN) {
+ u32 lat =
+ ((er32(PBA) & E1000_PBA_RXA_MASK) * 1024 -
+ adapter->max_frame_size) * 8 / 1000;
+
+ if (adapter->flags & FLAG_IS_ICH) {
u32 rxdctl = er32(RXDCTL(0));
ew32(RXDCTL(0), rxdctl | 0x3);
- pm_qos_update_request(&adapter->netdev->pm_qos_req, 55);
- } else {
- pm_qos_update_request(&adapter->netdev->pm_qos_req,
- PM_QOS_DEFAULT_VALUE);
}
+
+ pm_qos_update_request(&adapter->netdev->pm_qos_req, lat);
+ } else {
+ pm_qos_update_request(&adapter->netdev->pm_qos_req,
+ PM_QOS_DEFAULT_VALUE);
}
/* Enable Receives */
@@ -4281,10 +4286,8 @@
e1000_update_mng_vlan(adapter);
/* DMA latency requirement to workaround jumbo issue */
- if (adapter->hw.mac.type == e1000_pch2lan)
- pm_qos_add_request(&adapter->netdev->pm_qos_req,
- PM_QOS_CPU_DMA_LATENCY,
- PM_QOS_DEFAULT_VALUE);
+ pm_qos_add_request(&adapter->netdev->pm_qos_req, PM_QOS_CPU_DMA_LATENCY,
+ PM_QOS_DEFAULT_VALUE);
/* before we allocate an interrupt, we must be ready to handle it.
* Setting DEBUG_SHIRQ in the kernel makes it fire an interrupt
@@ -4392,8 +4395,7 @@
!test_bit(__E1000_TESTING, &adapter->state))
e1000e_release_hw_control(adapter);
- if (adapter->hw.mac.type == e1000_pch2lan)
- pm_qos_remove_request(&adapter->netdev->pm_qos_req);
+ pm_qos_remove_request(&adapter->netdev->pm_qos_req);
pm_runtime_put_sync(&pdev->dev);