From 8f4652848b36508394d0ce9eee27afeab5698a19 Mon Sep 17 00:00:00 2001 From: Vitaly Lifshits Date: Wed, 11 Jun 2025 15:52:54 +0300 Subject: [PATCH] igc: disable L1.2 PCI-E link substate to avoid performance issue [ Upstream commit 0325143b59c6c6d79987afc57d2456e7a20d13b7 ] I226 devices advertise support for the PCI-E link L1.2 substate. However, due to a hardware limitation, the exit latency from this low-power state is longer than the packet buffer can tolerate under high traffic conditions. This can lead to packet loss and degraded performance. To mitigate this, disable the L1.2 substate. The increased power draw between L1.1 and L1.2 is insignificant. Fixes: 43546211738e ("igc: Add new device ID's") Link: https://lore.kernel.org/intel-wired-lan/15248b4f-3271-42dd-8e35-02bfc92b25e1@intel.com Signed-off-by: Vitaly Lifshits Reviewed-by: Aleksandr Loktionov Tested-by: Mor Bar-Gabay Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/igc/igc_main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index e2f5c4384455..11543db4c47f 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -6772,6 +6772,10 @@ static int igc_probe(struct pci_dev *pdev, adapter->port_num = hw->bus.func; adapter->msg_enable = netif_msg_init(debug, DEFAULT_MSG_ENABLE); + /* Disable ASPM L1.2 on I226 devices to avoid packet loss */ + if (igc_is_device_id_i226(hw)) + pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2); + err = pci_save_state(pdev); if (err) goto err_ioremap; @@ -7144,6 +7148,9 @@ static int __maybe_unused igc_resume(struct device *dev) pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); + if (igc_is_device_id_i226(hw)) + pci_disable_link_state(pdev, PCIE_LINK_STATE_L1_2); + if (igc_init_interrupt_scheme(adapter, true)) { netdev_err(netdev, "Unable to allocate memory for queues\n"); return -ENOMEM; @@ -7259,6 +7266,9 @@ static pci_ers_result_t igc_io_slot_reset(struct pci_dev *pdev) pci_enable_wake(pdev, PCI_D3hot, 0); pci_enable_wake(pdev, PCI_D3cold, 0); + if (igc_is_device_id_i226(hw)) + pci_disable_link_state_locked(pdev, PCIE_LINK_STATE_L1_2); + /* In case of PCI error, adapter loses its HW address * so we should re-assign it here. */