drivers/firmware/dmi_scan.c: check dmi version when get system uuid

As of version 2.6 of the SMBIOS specification, the first 3 fields of the
UUID are supposed to be little-endian encoded.

Also a minor fix to match variable meaning and mute checkpatch.pl

[akpm@linux-foundation.org: tweak code comment]
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc: Feng Jin <joe.jin@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index b298158cb922..3714e3c03df6 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -16,6 +16,7 @@
  */
 static char dmi_empty_string[] = "        ";
 
+static u16 __initdata dmi_ver;
 /*
  * Catch too early calls to dmi_check_system():
  */
@@ -161,8 +162,10 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int inde
                 return;
 
         for (i = 0; i < 16 && (is_ff || is_00); i++) {
-                if(d[i] != 0x00) is_ff = 0;
-                if(d[i] != 0xFF) is_00 = 0;
+                if (d[i] != 0x00)
+                        is_00 = 0;
+                if (d[i] != 0xFF)
+                        is_ff = 0;
         }
 
         if (is_ff || is_00)
@@ -172,7 +175,15 @@ static void __init dmi_save_uuid(const struct dmi_header *dm, int slot, int inde
         if (!s)
                 return;
 
-        sprintf(s, "%pUB", d);
+        /*
+         * As of version 2.6 of the SMBIOS specification, the first 3 fields of
+         * the UUID are supposed to be little-endian encoded.  The specification
+         * says that this is the defacto standard.
+         */
+        if (dmi_ver >= 0x0206)
+                sprintf(s, "%pUL", d);
+        else
+                sprintf(s, "%pUB", d);
 
         dmi_ident[slot] = s;
 }
@@ -414,6 +425,7 @@ static int __init dmi_present(const char __iomem *p)
                  * DMI version 0.0 means that the real version is taken from
                  * the SMBIOS version, which we don't know at this point.
                  */
+                dmi_ver = (buf[14] & 0xf0) << 4 | (buf[14] & 0x0f);
                 if (buf[14] != 0)
                         printk(KERN_INFO "DMI %d.%d present.\n",
                                buf[14] >> 4, buf[14] & 0xF);