I tested the patchset on a Dell machine (the testing result is positive). Without the patchset, the ASPM is disabled on the NVME controller: LnkCtl: ASPM Disabled; RCB 64 bytes, Disabled- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- After applying the patchset, the ASPM is enabled on the NVME controller: LnkCtl: ASPM L1 Enabled; RCB 64 bytes, Disabled- CommClk+ ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt- Regards, Hui. On 5/30/24 16:52, Kai-Heng Feng wrote:
Since commit f492edb40b54 ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR"), ASPM is configured for NVMe devices enabled in VMD domain. However, that doesn't cover the case when FADT has ACPI_FADT_NO_ASPM set. So add a new attribute to bypass aspm_disabled so OS can configure ASPM. 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/pcie/aspm.c | 8 ++++++-- include/linux/pci.h | 1 + 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index cee2365e54b8..e719605857b1 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1416,8 +1416,12 @@ static int __pci_enable_link_state(struct pci_dev *pdev, int state, bool locked) * the _OSC method), we can't honor that request. */ if (aspm_disabled) { - pci_warn(pdev, "can't override BIOS ASPM; OS doesn't have ASPM control\n"); - return -EPERM; + if (aspm_support_enabled && pdev->aspm_os_control) + pci_info(pdev, "BIOS can't program ASPM, let OS control it\n"); + else { + pci_warn(pdev, "can't override BIOS ASPM; OS doesn't have ASPM control\n"); + return -EPERM; + } }if (!locked)diff --git a/include/linux/pci.h b/include/linux/pci.h index fb004fd4e889..58cbd4bea320 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -467,6 +467,7 @@ struct pci_dev { unsigned int no_command_memory:1; /* No PCI_COMMAND_MEMORY */ unsigned int rom_bar_overlap:1; /* ROM BAR disable broken */ unsigned int rom_attr_enabled:1; /* Display of ROM attribute enabled? */ + unsigned int aspm_os_control:1; /* Display of ROM attribute enabled? */ pci_dev_flags_t dev_flags; atomic_t enable_cnt; /* pci_enable_device has been called */
