| Message ID | 1536131573-15087-1-git-send-email-ptalbert@redhat.com |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [[v1] ] PCI/ASPM: Do not initialize link state when aspm_disabled is set | expand |
On Wed, Sep 05, 2018 at 09:12:53AM +0200, Patrick Talbert wrote: > 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. > > Fixes: 1302fcf ("PCI: Configure *all* devices, not just hot-added ones") > Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001 > Signed-off-by: Patrick Talbert <ptalbert@redhat.com> Applied to pci/aspm for v4.20, thanks! > --- > 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 53269167..4feb8ba 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -895,7 +895,7 @@ 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) > -- > 1.8.3.1 >
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 53269167..4feb8ba 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -895,7 +895,7 @@ 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)
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. Fixes: 1302fcf ("PCI: Configure *all* devices, not just hot-added ones") Link: https://bugzilla.kernel.org/show_bug.cgi?id=201001 Signed-off-by: Patrick Talbert <ptalbert@redhat.com> --- drivers/pci/pcie/aspm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)