3 files changed, 38 insertions, 21 deletions

diff --git a/arch/i386/kernel/dmi_scan.c b/arch/i386/kernel/dmi_scan.c
index ca2a0cbcac04..d2dfd9c8d691 100644
--- a/arch/i386/kernel/dmi_scan.c
+++ b/arch/i386/kernel/dmi_scan.c
@@ -299,3 +299,33 @@ struct dmi_device * dmi_find_device(int type, const char *name,
         return NULL;
 }
 EXPORT_SYMBOL(dmi_find_device);
+
+/**
+ *      dmi_get_year - Return year of a DMI date
+ *      @field: data index (like dmi_get_system_info)
+ *
+ *      Returns -1 when the field doesn't exist. 0 when it is broken.
+ */
+int dmi_get_year(int field)
+{
+        int year;
+        char *s = dmi_get_system_info(field);
+
+        if (!s)
+                return -1;
+        if (*s == '\0')
+                return 0;
+        s = strrchr(s, '/');
+        if (!s)
+                return 0;
+
+        s += 1;
+        year = simple_strtoul(s, NULL, 0);
+        if (year && year < 100) {       /* 2-digit year */
+                year += 1900;
+                if (year < 1996)        /* no dates < spec 1.0 */
+                        year += 100;
+        }
+
+        return year;
+}
diff --git a/drivers/acpi/blacklist.c b/drivers/acpi/blacklist.c
index 9824f679a910..f9c972b26f4f 100644
--- a/drivers/acpi/blacklist.c
+++ b/drivers/acpi/blacklist.c
@@ -77,28 +77,13 @@ static struct acpi_blacklist_item acpi_blacklist[] __initdata = {
 
 static int __init blacklist_by_year(void)
 {
-        int year;
-        char *s = dmi_get_system_info(DMI_BIOS_DATE);
-
-        if (!s)
-                return 0;
-        if (!*s)
-                return 0;
-
-        s = strrchr(s, '/');
-        if (!s)
+        int year = dmi_get_year(DMI_BIOS_DATE);
+        /* Doesn't exist? Likely an old system */
+        if (year == -1) 
+                return 1;
+        /* 0? Likely a buggy new BIOS */
+        if (year == 0)
                 return 0;
-
-        s += 1;
-
-        year = simple_strtoul(s, NULL, 0);
-
-        if (year < 100) {       /* 2-digit year */
-                year += 1900;
-                if (year < 1996)        /* no dates < spec 1.0 */
-                        year += 100;
-        }
-
         if (year < CONFIG_ACPI_BLACKLIST_YEAR) {
                 printk(KERN_ERR PREFIX "BIOS age (%d) fails cutoff (%d), "
                        "acpi=force is required to enable ACPI\n",
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index 2e6bbe014157..64fd6c366604 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -68,6 +68,7 @@ extern char * dmi_get_system_info(int field);
 extern struct dmi_device * dmi_find_device(int type, const char *name,
         struct dmi_device *from);
 extern void dmi_scan_machine(void);
+extern int dmi_get_year(int field);
 
 #else
 
@@ -75,6 +76,7 @@ static inline int dmi_check_system(struct dmi_system_id *list) { return 0; }
 static inline char * dmi_get_system_info(int field) { return NULL; }
 static inline struct dmi_device * dmi_find_device(int type, const char *name,
         struct dmi_device *from) { return NULL; }
+static inline int dmi_get_year(int year) { return 0; }
 
 #endif