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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.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index f82495583e63..9a7c9e1408a4 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -55,7 +55,7 @@ struct pcie_link_state {
struct endpoint_state endpoints[8];
};
-static int aspm_disabled;
+static int aspm_disabled, aspm_force;
static DEFINE_MUTEX(aspm_lock);
static LIST_HEAD(link_list);
@@ -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 +520,19 @@ 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 && !aspm_force)) {
+ printk("Pre-1.1 PCIe device detected, "
+ "disable ASPM for %s. It can be enabled forcedly"
+ " with 'pcie_aspm=force'\n", pci_name(pdev));
+ return -EINVAL;
+ }
}
return 0;
}
@@ -802,11 +816,23 @@ void pcie_aspm_remove_sysfs_dev_files(struct pci_dev *pdev)
static int __init pcie_aspm_disable(char *str)
{
- aspm_disabled = 1;
+ if (!strcmp(str, "off")) {
+ aspm_disabled = 1;
+ printk(KERN_INFO "PCIe ASPM is disabled\n");
+ } else if (!strcmp(str, "force")) {
+ aspm_force = 1;
+ printk(KERN_INFO "PCIe ASPM is forcedly enabled\n");
+ }
return 1;
}
-__setup("pcie_noaspm", pcie_aspm_disable);
+__setup("pcie_aspm=", pcie_aspm_disable);
+
+void pcie_no_aspm(void)
+{
+ if (!aspm_force)
+ aspm_disabled = 1;
+}
#ifdef CONFIG_ACPI
#include <acpi/acpi_bus.h>