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path: root/drivers/pci/pcie/aspm.c
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Diffstat (limited to 'drivers/pci/pcie/aspm.c')
-rw-r--r--drivers/pci/pcie/aspm.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 759c51a4e39..704605298c5 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -510,6 +510,7 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
{
struct pci_dev *child_dev;
int child_pos;
+ u32 reg32;
/*
* Some functions in a slot might not all be PCIE functions, very
@@ -519,6 +520,18 @@ static int pcie_aspm_sanity_check(struct pci_dev *pdev)
child_pos = pci_find_capability(child_dev, PCI_CAP_ID_EXP);
if (!child_pos)
return -EINVAL;
+
+ /*
+ * Disable ASPM for pre-1.1 PCIe device, we follow MS to use
+ * RBER bit to determine if a function is 1.1 version device
+ */
+ pci_read_config_dword(child_dev, child_pos + PCI_EXP_DEVCAP,
+ &reg32);
+ if (!(reg32 & PCI_EXP_DEVCAP_RBER)) {
+ printk("Pre-1.1 PCIe device detected, "
+ "disable ASPM for %s\n", pci_name(pdev));
+ return -EINVAL;
+ }
}
return 0;
}