From: Vitaly Lifshits Date: Wed, 11 Jun 2025 12:52:54 +0000 (+0300) Subject: igc: disable L1.2 PCI-E link substate to avoid performance issue X-Git-Tag: v5.15.187~42 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f5874e0dea9e4b496626860d5f6840c848afe90c;p=thirdparty%2Fkernel%2Fstable.git 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 --- diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index 4186e5732f972..f52c1674d19bd 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -6549,6 +6549,10 @@ 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; @@ -6914,6 +6918,9 @@ 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; @@ -7029,6 +7036,9 @@ 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. */