diff options
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 114e2067dce..a24d3461fc7 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -893,11 +893,26 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget, } /* - * 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. + * Some targets may set slight variations of PQ and PDT to signal + * that no LUN is present, so don't add sdev in these cases. + * Two specific examples are: + * 1) NetApp targets: return PQ=1, PDT=0x1f + * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" + * in the UFI 1.0 spec (we cannot rely on reserved bits). + * + * References: + * 1) SCSI SPC-3, pp. 145-146 + * PQ=1: "A peripheral device having the specified peripheral + * device type is not connected to this logical unit. However, the + * device server is capable of supporting the specified peripheral + * device type on this logical unit." + * PDT=0x1f: "Unknown or no device type" + * 2) USB UFI 1.0, p. 20 + * PDT=00h Direct-access device (floppy) + * PDT=1Fh none (no FDD connected to the requested logical unit) */ - if (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f) { + if (((result[0] >> 5) == 1 || 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")); |