[SCSI] Recognize missing LUNs for non-standard devices
Some non-standard SCSI targets or protocols, such as USB UFI, report "no
LUN present" by setting the Peripheral Device Type to 0x1f and the
Peripheral Qualifier to 0 (not 3 as the standard requires) in the INQUIRY
response. This patch (as650b) adds a new target flag and code to
accomodate such targets.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 803c7b9..94b86d5b1 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -853,6 +853,19 @@
goto out_free_result;
}
+ /*
+ * Non-standard SCSI targets may set the PDT to 0x1f (unknown or
+ * no device type) instead of using the Peripheral Qualifier to
+ * indicate that no LUN is present. For example, USB UFI does this.
+ */
+ if (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f) {
+ SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
+ "scsi scan: peripheral device type"
+ " of 31, no device added\n"));
+ res = SCSI_SCAN_TARGET_PRESENT;
+ goto out_free_result;
+ }
+
res = scsi_add_lun(sdev, result, &bflags);
if (res == SCSI_SCAN_LUN_PRESENT) {
if (bflags & BLIST_KEY) {
