// SPDX-License-Identifier: ISC /* * Copyright (C) 2019 Lorenzo Bianconi <lorenzo@kernel.org> */ #include "mt76.h" #include <linux/pci.h> void mt76_pci_disable_aspm(struct pci_dev *pdev) { struct pci_dev *parent = pdev->bus->self; u16 aspm_conf, parent_aspm_conf = 0; pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &aspm_conf); aspm_conf &= PCI_EXP_LNKCTL_ASPMC; if (parent) { pcie_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_aspm_conf); parent_aspm_conf &= PCI_EXP_LNKCTL_ASPMC; } if (!aspm_conf && (!parent || !parent_aspm_conf)) { /* aspm already disabled */ return; } dev_info(&pdev->dev, "disabling ASPM %s %s\n", (aspm_conf & PCI_EXP_LNKCTL_ASPM_L0S) ? "L0s" : "", (aspm_conf & PCI_EXP_LNKCTL_ASPM_L1) ? "L1" : ""); if (IS_ENABLED(CONFIG_PCIEASPM)) { int err; err = pci_disable_link_state(pdev, aspm_conf); if (!err) return; } /* both device and parent should have the same ASPM setting. * disable ASPM in downstream component first and then upstream. */ pcie_capability_clear_word(pdev, PCI_EXP_LNKCTL, aspm_conf); if (parent) pcie_capability_clear_word(parent, PCI_EXP_LNKCTL, aspm_conf); } EXPORT_SYMBOL_GPL(mt76_pci_disable_aspm);