diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 32 |
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, + ®32); + 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> |