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| author | David E. Box <david.e.box@linux.intel.com> | 2024-02-23 14:58:50 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-03-12 11:53:45 -0500 |
| commit | 17423360a27ae58c1850f588bdd8013bbfcd250b (patch) | |
| tree | a73ad2284661342aa66cdbc38f89eaf3c9544104 /drivers/pci/pci.h | |
| parent | 1e11b5494c3dbb1e5fce7e95021c1698799c7288 (diff) | |
| download | lwn-17423360a27ae58c1850f588bdd8013bbfcd250b.tar.gz lwn-17423360a27ae58c1850f588bdd8013bbfcd250b.zip | |
PCI/ASPM: Save L1 PM Substates Capability for suspend/resume
4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume") restored the L1 PM Substates Capability after resume,
which reduced power consumption by making the ASPM L1.x states work after
resume.
a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability for
suspend/resume"") reverted 4ff116d0d5fd because resume failed on some
systems, so power consumption after resume increased again.
a7152be79b62 mentioned that we restore L1 PM substate configuration even
though ASPM L1 may already be enabled. This is due the fact that the
pci_restore_aspm_l1ss_state() was called before pci_restore_pcie_state().
Save and restore the L1 PM Substates Capability, following PCIe r6.1, sec
5.5.4 more closely by:
1) Do not restore ASPM configuration in pci_restore_pcie_state() but
do that after PCIe capability is restored in pci_restore_aspm_state()
following PCIe r6.1, sec 5.5.4.
2) If BIOS reenables L1SS, particularly L1.2, we need to clear the
enables in the right order, downstream before upstream. Defer
restoring the L1SS config until we are at the downstream component.
Then update the config for both ends of the link in the prescribed
order.
3) Program ASPM L1 PM substate configuration before L1 enables.
4) Program ASPM L1 PM substate enables last, after rest of the fields
in the capability are programmed.
[bhelgaas: commit log, squash L1SS-related patches, do both LNKCTL restores
in pci_restore_pcie_state()]
Link: https://lore.kernel.org/r/20240128233212.1139663-3-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240128233212.1139663-4-david.e.box@linux.intel.com
Link: https://lore.kernel.org/r/20240223205851.114931-5-helgaas@kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217321
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216782
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216877
Co-developed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Co-developed-by: David E. Box <david.e.box@linux.intel.com>
Reported-by: Koba Ko <koba.ko@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Tasev Nikola <tasev.stefanoska@skynet.be> # Asus UX305FA
Cc: Mark Enriquez <enriquezmark36@gmail.com>
Cc: Thomas Witt <kernel@witt.link>
Cc: Werner Sembach <wse@tuxedocomputers.com>
Cc: Vidya Sagar <vidyas@nvidia.com>
Diffstat (limited to 'drivers/pci/pci.h')
| -rw-r--r-- | drivers/pci/pci.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index ad3add45345c..eca5938deb07 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -571,6 +571,9 @@ int pcie_retrain_link(struct pci_dev *pdev, bool use_lt); /* ASPM-related functionality we need even without CONFIG_PCIEASPM */ void pci_save_ltr_state(struct pci_dev *dev); void pci_restore_ltr_state(struct pci_dev *dev); +void pci_configure_aspm_l1ss(struct pci_dev *dev); +void pci_save_aspm_l1ss_state(struct pci_dev *dev); +void pci_restore_aspm_l1ss_state(struct pci_dev *dev); #ifdef CONFIG_PCIEASPM void pcie_aspm_init_link_state(struct pci_dev *pdev); |