[PATCH 2/2] PCI: vmd: Let OS control ASPM for devices under VMD domain

From: Kai-Heng Feng
Date: Thu May 30 2024 - 04:53:23 EST


Intel SoC cannot reach lower power states when mapped VMD PCIe bridges
and NVMe devices don't have ASPM configured.

So set aspm_os_control attribute to let OS really enable ASPM for those
devices.

Fixes: f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/linux-pm/218aa81f-9c6-5929-578d-8dc15f83dd48@xxxxxxxxx/
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
---
drivers/pci/controller/vmd.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 87b7856f375a..1dbc525c473f 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -751,6 +751,8 @@ static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
return 0;

+ pdev->aspm_os_control = 1;
+
pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);

pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
--
2.43.0