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-rw-r--r--drivers/acpi/pci_root.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 7433035ded95..707aafc7c2aa 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -421,7 +421,8 @@ out:
}
EXPORT_SYMBOL(acpi_pci_osc_control_set);
-static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+ bool is_pcie)
{
u32 support, control, requested;
acpi_status status;
@@ -455,9 +456,15 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
decode_osc_support(root, "OS supports", support);
status = acpi_pci_osc_support(root, support);
if (ACPI_FAILURE(status)) {
- dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
- acpi_format_exception(status));
*no_aspm = 1;
+
+ /* _OSC is optional for PCI host bridges */
+ if ((status == AE_NOT_FOUND) && !is_pcie)
+ return;
+
+ dev_info(&device->dev, "_OSC failed (%s)%s\n",
+ acpi_format_exception(status),
+ pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
return;
}
@@ -533,6 +540,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
acpi_handle handle = device->handle;
int no_aspm = 0;
bool hotadd = system_state == SYSTEM_RUNNING;
+ bool is_pcie;
root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
if (!root)
@@ -590,7 +598,8 @@ static int acpi_pci_root_add(struct acpi_device *device,
root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
- negotiate_os_control(root, &no_aspm);
+ is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
+ negotiate_os_control(root, &no_aspm, is_pcie);
/*
* TBD: Need PCI interface for enumeration/configuration of roots.