From: Patrick Talbert ptalbert@redhat.com
[ Upstream commit 17c91487364fb33797ed84022564ee7544ac4945 ]
Now that ASPM is configured for *all* PCIe devices at boot, a problem is seen with systems that set the FADT NO_ASPM bit. This bit indicates that the OS should not alter the ASPM state, but when pcie_aspm_init_link_state() runs it only checks for !aspm_support_enabled. This misses the ACPI_FADT_NO_ASPM case because that is setting aspm_disabled.
The result is systems may hang at boot after 1302fcf; avoidable if they boot with pcie_aspm=off (sets !aspm_support_enabled).
Fix this by having aspm_init_link_state() check for either !aspm_support_enabled or acpm_disabled.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001 Fixes: 1302fcf0d03e ("PCI: Configure *all* devices, not just hot-added ones") Signed-off-by: Patrick Talbert ptalbert@redhat.com Signed-off-by: Bjorn Helgaas bhelgaas@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/pcie/aspm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 6b4e82a4b64e0..370c3459e8845 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -858,7 +858,7 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) struct pcie_link_state *link; int blacklist = !!pcie_aspm_sanity_check(pdev);
- if (!aspm_support_enabled) + if (!aspm_support_enabled || aspm_disabled) return;
if (pdev->link_state)