1 files changed, 29 insertions, 2 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 875eadd5e8f5..3f873cc7e247 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -194,6 +194,27 @@ MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
         ", or a combination)");
 
+/*
+ * This influences the format of the sysfs attribute
+ * /sys/bus/scsi/devices/.../ieee1394_id.
+ *
+ * The default format is like in older kernels:  %016Lx:%d:%d
+ * It contains the target's EUI-64, a number given to the logical unit by
+ * the ieee1394 driver's nodemgr (starting at 0), and the LUN.
+ *
+ * The long format is:  %016Lx:%06x:%04x
+ * It contains the target's EUI-64, the unit directory's directory_ID as per
+ * IEEE 1212 clause 7.7.19, and the LUN.  This format comes closest to the
+ * format of SBP(-3) target port and logical unit identifier as per SAM (SCSI
+ * Architecture Model) rev.2 to 4 annex A.  Therefore and because it is
+ * independent of the implementation of the ieee1394 nodemgr, the longer format
+ * is recommended for future use.
+ */
+static int sbp2_long_sysfs_ieee1394_id;
+module_param_named(long_ieee1394_id, sbp2_long_sysfs_ieee1394_id, bool, 0644);
+MODULE_PARM_DESC(long_ieee1394_id, "8+3+2 bytes format of ieee1394_id in sysfs "
+                 "(default = backwards-compatible = N, SAM-conforming = Y)");
+
 
 #define SBP2_INFO(fmt, args...) HPSB_INFO("sbp2: "fmt, ## args)
 #define SBP2_ERR(fmt, args...)  HPSB_ERR("sbp2: "fmt, ## args)
@@ -2100,8 +2121,14 @@ static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
         if (!(lu = (struct sbp2_lu *)sdev->host->hostdata[0]))
                 return 0;
 
-        return sprintf(buf, "%016Lx:%d:%d\n", (unsigned long long)lu->ne->guid,
-                       lu->ud->id, ORB_SET_LUN(lu->lun));
+        if (sbp2_long_sysfs_ieee1394_id)
+                return sprintf(buf, "%016Lx:%06x:%04x\n",
+                                (unsigned long long)lu->ne->guid,
+                                lu->ud->directory_id, ORB_SET_LUN(lu->lun));
+        else
+                return sprintf(buf, "%016Lx:%d:%d\n",
+                                (unsigned long long)lu->ne->guid,
+                                lu->ud->id, ORB_SET_LUN(lu->lun));
 }
 
 MODULE_AUTHOR("Ben Collins <bcollins@debian.org>");