2 files changed, 40 insertions, 0 deletions

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index fb7fc24fe727..189cbc2585fa 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -8,6 +8,7 @@
 #include <linux/acpi.h>
 #include <linux/signal.h>
 #include <linux/kthread.h>
+#include <linux/dmi.h>
 
 #include <acpi/acpi_drivers.h>
 
@@ -1032,6 +1033,41 @@ static void acpi_add_id(struct acpi_device *device, const char *dev_id)
         list_add_tail(&id->list, &device->pnp.ids);
 }
 
+/*
+ * Old IBM workstations have a DSDT bug wherein the SMBus object
+ * lacks the SMBUS01 HID and the methods do not have the necessary "_"
+ * prefix.  Work around this.
+ */
+static int acpi_ibm_smbus_match(struct acpi_device *device)
+{
+        acpi_handle h_dummy;
+        struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
+        int result;
+
+        if (!dmi_name_in_vendors("IBM"))
+                return -ENODEV;
+
+        /* Look for SMBS object */
+        result = acpi_get_name(device->handle, ACPI_SINGLE_NAME, &path);
+        if (result)
+                return result;
+
+        if (strcmp("SMBS", path.pointer)) {
+                result = -ENODEV;
+                goto out;
+        }
+
+        /* Does it have the necessary (but misnamed) methods? */
+        result = -ENODEV;
+        if (ACPI_SUCCESS(acpi_get_handle(device->handle, "SBI", &h_dummy)) &&
+            ACPI_SUCCESS(acpi_get_handle(device->handle, "SBR", &h_dummy)) &&
+            ACPI_SUCCESS(acpi_get_handle(device->handle, "SBW", &h_dummy)))
+                result = 0;
+out:
+        kfree(path.pointer);
+        return result;
+}
+
 static void acpi_device_set_id(struct acpi_device *device)
 {
         acpi_status status;
@@ -1082,6 +1118,8 @@ static void acpi_device_set_id(struct acpi_device *device)
                         acpi_add_id(device, ACPI_BAY_HID);
                 else if (ACPI_SUCCESS(acpi_dock_match(device)))
                         acpi_add_id(device, ACPI_DOCK_HID);
+                else if (!acpi_ibm_smbus_match(device))
+                        acpi_add_id(device, ACPI_SMBUS_IBM_HID);
 
                 break;
         case ACPI_BUS_TYPE_POWER:
diff --git a/include/acpi/acpi_drivers.h b/include/acpi/acpi_drivers.h
index 3a4767c01c5f..4f7b44866b76 100644
--- a/include/acpi/acpi_drivers.h
+++ b/include/acpi/acpi_drivers.h
@@ -65,6 +65,8 @@
 #define ACPI_VIDEO_HID                  "LNXVIDEO"
 #define ACPI_BAY_HID                    "LNXIOBAY"
 #define ACPI_DOCK_HID                   "LNXDOCK"
+/* Quirk for broken IBM BIOSes */
+#define ACPI_SMBUS_IBM_HID              "SMBUSIBM"
 
 /*
  * For fixed hardware buttons, we fabricate acpi_devices with HID