Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
PCI/ASPM: Add pcie_aspm_remove_cap() to override advertised link states
Add pcie_aspm_remove_cap(). A quirk can use this to prevent use of ASPM
L0s or L1 link states, even if the device advertised support for them.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://patch.msgid.link/20251110222929.2140564-3-helgaas@kernel.org
+15
+2
drivers/pci/pci.h
+2
drivers/pci/pci.h
···
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void pci_restore_aspm_l1ss_state(struct pci_dev *dev);
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#ifdef CONFIG_PCIEASPM
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void pcie_aspm_remove_cap(struct pci_dev *pdev, u32 lnkcap);
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void pcie_aspm_init_link_state(struct pci_dev *pdev);
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void pcie_aspm_exit_link_state(struct pci_dev *pdev);
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void pcie_aspm_pm_state_change(struct pci_dev *pdev, bool locked);
···
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void pci_configure_ltr(struct pci_dev *pdev);
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void pci_bridge_reconfigure_ltr(struct pci_dev *pdev);
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#else
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static inline void pcie_aspm_remove_cap(struct pci_dev *pdev, u32 lnkcap) { }
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static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { }
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static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { }
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static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev, bool locked) { }
+13
drivers/pci/pcie/aspm.c
+13
drivers/pci/pcie/aspm.c
···
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}
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EXPORT_SYMBOL(pci_enable_link_state_locked);
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void pcie_aspm_remove_cap(struct pci_dev *pdev, u32 lnkcap)
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{
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if (lnkcap & PCI_EXP_LNKCAP_ASPM_L0S)
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pdev->aspm_l0s_support = 0;
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if (lnkcap & PCI_EXP_LNKCAP_ASPM_L1)
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pdev->aspm_l1_support = 0;
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+
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pci_info(pdev, "ASPM: Link Capabilities%s%s treated as unsupported to avoid device defect\n",
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lnkcap & PCI_EXP_LNKCAP_ASPM_L0S ? " L0s" : "",
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lnkcap & PCI_EXP_LNKCAP_ASPM_L1 ? " L1" : "");
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}
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static int pcie_aspm_set_policy(const char *val,
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const struct kernel_param *kp)
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{