Commit 1bfc5d9d authored by Alan Stern's avatar Alan Stern Committed by James Bottomley
Browse files

[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: default avatarAlan Stern <>
Signed-off-by: default avatarJames Bottomley <>
parent 8cac8145
......@@ -853,6 +853,19 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
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 scan: peripheral device type"
" of 31, no device added\n"));
goto out_free_result;
res = scsi_add_lun(sdev, result, &bflags);
if (bflags & BLIST_KEY) {
......@@ -167,7 +167,10 @@ struct scsi_target {
unsigned int channel;
unsigned int id; /* target id ... replace
* eventually */
unsigned long create:1; /* signal that it needs to be added */
unsigned int create:1; /* signal that it needs to be added */
unsigned int pdt_1f_for_no_lun; /* PDT = 0x1f */
/* means no lun present */
char scsi_level;
void *hostdata; /* available to low-level driver */
unsigned long starget_data[0]; /* for the transport */
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