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UBUNTU: SAUCE: PCI: ASPM: Allow OS to configure ASPM where BIOS is incapable of

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BugLink: https://bugs.launchpad.net/bugs/2072679

Since commit f492edb40b ("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: f492edb40b ("PCI: vmd: Add quirk to configure PCIe ASPM and LTR")
Link: https://lore.kernel.org/linux-pm/218aa81f-9c6-5929-578d-8dc15f83dd48@panix.com/
(cherry picked from https://lore.kernel.org/linux-pci/20240530085227.91168-1-kai.heng.feng@canonical.com/)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Hui Wang <hui.wang@canonical.com>
Acked-by: Aaron Jauregui <aaron.jauregui@canonical.com>
Acked-by: Kuan-Ying Lee <kuan-ying.lee@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
This commit is contained in:
Kai-Heng Feng
2024-08-19 10:59:07 +08:00
committed by Stefan Bader
parent ad3a83cfb9
commit 4cfe58fcb2
2 changed files with 7 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/pci/pcie/aspm.c
+6 -2
View File
@@ -1407,8 +1407,12 @@ 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)
include/linux/pci.h
+1
View File
@@ -465,6 +465,7 @@ 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 */