On 30.04.2019 19:53, Bjorn Helgaas wrote: > On Sat, Apr 13, 2019 at 11:12:41AM +0200, Heiner Kallweit wrote: >> Background of this extension is a problem with the r8169 network driver. >> Several combinations of board chipsets and network chip versions have >> problems if ASPM is enabled, therefore we have to disable ASPM per >> default. However especially on notebooks ASPM can provide significant >> power-saving, therefore we want to give users the option to enable >> ASPM. With the new sysfs attribute users can control which ASPM >> link-states are disabled. > >> +void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); >> +void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); >> #else >> static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { } >> static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { } >> static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { } >> static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { } >> -#endif >> - >> -#ifdef CONFIG_PCIEASPM_DEBUG >> -void pcie_aspm_create_sysfs_dev_files(struct pci_dev *pdev); >> -void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev); >> -#else > > I like the idea of exposing these sysfs control files all the time, > instead of only when CONFIG_PCIEASPM_DEBUG=y, but I think when we do > that, we should put the files at the downstream end of the link (e.g., > an endpoint) instead of at the upstream end (e.g., a root port or > switch downstream port). We had some conversation about this here: > > https://lore.kernel.org/lkml/20180727202619.GD173328@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > > Doing it at the downstream end would require more changes, of course, > and probably raises some locking issues, but I think we have a small > window of opportunity here where we can tweak the sysfs structure > before we're committed to supporting something forever. > Thanks for the feedback. I'll check the mentioned conversation and try to get the control moved to the endpoint. > Bjorn > Heiner