On Fri, Mar 10, 2023 at 09:42:04PM +0100, Heiner Kallweit wrote: > On 09.03.2023 21:17, Bjorn Helgaas wrote: > > On Sat, Feb 25, 2023 at 11:46:33AM +0800, Kai-Heng Feng wrote: > >> To really enable ASPM on r8169 NICs, both standard PCIe ASPM and > >> chip-specific ASPM have to be enabled at the same time. > >> > >> Before enabling ASPM at chip side, make sure the following conditions > >> are met: > >> 1) Use pcie_aspm_support_enabled() to check if ASPM is disabled by > >> kernel parameter. > >> 2) Use pcie_aspm_capable() to see if the device is capable to perform > >> PCIe ASPM. > >> 3) Check the return value of pci_disable_link_state(). If it's -EPERM, > >> it means BIOS doesn't grant ASPM control to OS, and device should use > >> the ASPM setting as is. > >> > >> Consider ASPM is manageable when those conditions are met. > >> > >> While at it, disable ASPM at chip-side for TX timeout reset, since > >> pci_disable_link_state() doesn't have any effect when OS isn't granted > >> with ASPM control. > > > > 1) "While at it, ..." is always a hint that maybe this part could be > > split to a separate patch. > > > > 2) The mix of chip-specific and standard PCIe ASPM configuration is a > > mess. Does it *have* to be intermixed at run-time, or could all the > > chip-specific stuff be done once, e.g., maybe chip-specific ASPM > > enable could be done at probe-time, and then all subsequent ASPM > > configuration could done via the standard PCIe registers? > > > > I.e., does the chip work correctly if chip-specific ASPM is enabled, > > but standard PCIe ASPM config is *disabled*? > > > > The ASPM sysfs controls [1] assume that L0s, L1, L1.1, L1.2 can all be > > controlled simply by using the standard PCIe registers. If that's not > > the case for r8169, things will break when people use the sysfs knobs. > > > This series has been superseded meanwhile and what is being discussed > here has become obsolete. For completeness, I guess the replacement of this series is: https://lore.kernel.org/all/af076f1f-a034-82e5-8f76-f3ec32a14eaa@xxxxxxxxx/
