1a680b7c32
v3 -> v2: Moved ASPM enabling logic to pci_set_power_state() v2 -> v1: Preserved the logic in pci_raw_set_power_state() : Added ASPM enabling logic after scanning Root Bridge : http://marc.info/?l=linux-pci&m=130046996216391&w=2 v1 : http://marc.info/?l=linux-pci&m=130013164703283&w=2 The assumption made in commit41cd766b06(PCI: Don't enable aspm before drivers have had a chance to veto it) that pci_enable_device() will result in re-configuring ASPM when aspm_policy is POWERSAVE is no longer valid. This is due to commit97c145f7c8(PCI: read current power state at enable time) which resets dev->current_state to D0. Due to this the call to pcie_aspm_pm_state_change() is never made. Note the equality check (below) that returns early: ./drivers/pci/pci.c: pci_raw_set_pci_power_state() 546 /* Check if we're already there */ 547 if (dev->current_state == state) 548 return 0; Therefore OSPM never configures the PCIe links for ASPM to turn them "on". Fix it by configuring ASPM from the pci_enable_device() code path. This also allows a driver such as the e1000e networking driver a chance to disable ASPM (L0s, L1), if need be, prior to enabling the device. A driver may perform this action if the device is known to mis-behave wrt ASPM. Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
/*
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* aspm.h
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*
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* PCI Express ASPM defines and function prototypes
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*
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* Copyright (C) 2007 Intel Corp.
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* Zhang Yanmin (yanmin.zhang@intel.com)
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* Shaohua Li (shaohua.li@intel.com)
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*
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* For more information, please consult the following manuals (look at
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* http://www.pcisig.com/ for how to get them):
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*
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* PCI Express Specification
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*/
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#ifndef LINUX_ASPM_H
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#define LINUX_ASPM_H
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#include <linux/pci.h>
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#define PCIE_LINK_STATE_L0S 1
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#define PCIE_LINK_STATE_L1 2
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#define PCIE_LINK_STATE_CLKPM 4
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#ifdef CONFIG_PCIEASPM
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extern void pcie_aspm_init_link_state(struct pci_dev *pdev);
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extern void pcie_aspm_exit_link_state(struct pci_dev *pdev);
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extern void pcie_aspm_pm_state_change(struct pci_dev *pdev);
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extern void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
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extern void pci_disable_link_state(struct pci_dev *pdev, int state);
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extern void pcie_clear_aspm(void);
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extern void pcie_no_aspm(void);
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#else
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static inline void pcie_aspm_init_link_state(struct pci_dev *pdev)
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{
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}
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static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev)
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{
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}
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static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev)
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{
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}
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static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev)
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{
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}
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static inline void pci_disable_link_state(struct pci_dev *pdev, int state)
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{
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}
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static inline void pcie_clear_aspm(void)
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{
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}
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static inline void pcie_no_aspm(void)
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{
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}
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#endif
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#ifdef CONFIG_PCIEASPM_DEBUG /* this depends on CONFIG_PCIEASPM */
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extern void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev);
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extern void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev);
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#else
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static inline void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev)
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{
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}
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static inline void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
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{
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}
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#endif
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#endif /* LINUX_ASPM_H */
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