From stern@rowland.harvard.edu Mon Aug 21 09:00:54 2006 Date: Mon, 21 Aug 2006 12:00:53 -0400 (EDT) From: Alan Stern To: Greg KH , Matthew Dharm cc: USB Storage list Subject: usb-storage: fix for UFI LUN detection Message-ID: The UFI specification doesn't permit devices to indicate non-existent LUNs in the manner prescribed by the SCSI spec. This patch (as773) sets a special flag so that the SCSI scanner will recognize these devices and treat them specially. Signed-off-by: Alan Stern Signed-off-by: Matthew Dharm Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/scsiglue.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- gregkh-2.6.orig/drivers/usb/storage/scsiglue.c +++ gregkh-2.6/drivers/usb/storage/scsiglue.c @@ -72,12 +72,27 @@ static const char* host_info(struct Scsi static int slave_alloc (struct scsi_device *sdev) { + struct us_data *us = host_to_us(sdev->host); + /* * Set the INQUIRY transfer length to 36. We don't use any of * the extra data and many devices choke if asked for more or * less than 36 bytes. */ sdev->inquiry_len = 36; + + /* + * The UFI spec treates the Peripheral Qualifier bits in an + * INQUIRY result as reserved and requires devices to set them + * to 0. However the SCSI spec requires these bits to be set + * to 3 to indicate when a LUN is not present. + * + * Let the scanning code know if this target merely sets + * Peripheral Device Type to 0x1f to indicate no LUN. + */ + if (us->subclass == US_SC_UFI) + sdev->sdev_target->pdt_1f_for_no_lun = 1; + return 0; }