ACPI: Disable MSI on request of FADT

The ACPI spec defines the bit and Microsoft uses it,
so Linux must use it too.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index a064f36a0805d605e3e3edbf5ed87be5c7ee3819..b5ac810404c0f19dc98318dfe8dde6212d04c2bb 100644 (file)
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -317,6 +317,10 @@ static int __init acpi_pci_init(void)
 {
        int ret;
 
+       if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
+               printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
+               pci_no_msi();
+       }
        ret = register_acpi_bus_type(&acpi_pci_bus);
        if (ret)
                return 0;

diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h
index 09469e7db6a542e6ae7ebbc8d1125b9d5e1c59e7..955adfb8d64c2358d0c7f449a51adc93ecd964bd 100644 (file)
--- a/include/acpi/actbl.h
+++ b/include/acpi/actbl.h
@@ -276,6 +276,7 @@ enum acpi_prefered_pm_profiles {
 
 #define BAF_LEGACY_DEVICES              0x0001
 #define BAF_8042_KEYBOARD_CONTROLLER    0x0002
+#define BAF_MSI_NOT_SUPPORTED           0x0008
 
 #define FADT2_REVISION_ID               3
 #define FADT2_MINUS_REVISION_ID         2