diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 61fedb2448b6..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); @@ -506,6 +506,37 @@ static void free_link_state(struct pci_dev *pdev) pdev->link_state = NULL; } +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 + * strange. Disable ASPM for the whole slot + */ + list_for_each_entry(child_dev, &pdev->subordinate->devices, bus_list) { + 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; +} + /* * pcie_aspm_init_link_state: Initiate PCI express link state. * It is called after the pcie and its children devices are scaned. @@ -526,6 +557,9 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) if (list_empty(&pdev->subordinate->devices)) goto out; + if (pcie_aspm_sanity_check(pdev)) + goto out; + mutex_lock(&aspm_lock); link_state = kzalloc(sizeof(*link_state), GFP_KERNEL); @@ -782,11 +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> |