On Wed, 2022-12-07 at 22:05 +1300, Luke Jones wrote: > On Wed, 2022-11-02 at 19:18 -0700, David E. Box wrote: > > This series adds a work around for enabling PCIe ASPM and for setting > > PCIe > > LTR values on VMD reserved root ports on select platforms. While > > configuration of these capabilities is usually done by BIOS, on these > > platforms these capabilities will not be configured because the ports > > are > > not visible to BIOS. This was part of an initial design that expected > > the > > driver to completely handle the ports, including power management. > > However > > on Linux those ports are still managed by the PCIe core, which has > > the > > expectation that they adhere to device standards including BIOS > > configuration, leading to this problem. > > > > The target platforms are Tiger Lake, Alder Lake, and Raptor Lake > > though the > > latter has already implemented support for configuring the LTR > > values. > > Meteor Lake is expected add BIOS ASPM support, eliminating the future > > need > > for this work around. > > > > Note, the driver programs the LTRs because BIOS would also normally > > do this > > for devices that do not set them by default. Without this, SoC power > > management would be blocked on those platform. This SoC specific > > value is > > the maximum latency required to allow the SoC to enter the deepest > > power > > state. > > > > This patch addresses the following open bugzillas on VMD enabled > > laptops > > that cannot enter low power states. > > > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=212355 > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=215063 > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=213717 > > > > David E. Box (3): > > PCI: vmd: Use PCI_VDEVICE in device list > > PCI: vmd: Create feature grouping for client products > > PCI: vmd: Add quirk to configure PCIe ASPM and LTR > > > > Michael Bottini (1): > > PCI/ASPM: Add pci_enable_link_state() > > > > drivers/pci/controller/vmd.c | 96 ++++++++++++++++++++++++++-------- > > -- > > drivers/pci/pcie/aspm.c | 54 ++++++++++++++++++++ > > include/linux/pci.h | 7 +++ > > 3 files changed, 131 insertions(+), 26 deletions(-) > > > > > > base-commit: 247f34f7b80357943234f93f247a1ae6b6c3a740 > > I'd like to confirm that this patch series solves the VMD power issues > present on the ASUS ROG M16 (GU603) laptop range (PCI dev ID = 467f). > > The difference is quite drastic. > Thanks for testing this Luke. David
