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Commit 3a3416b1 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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usb-storage: fix for UFI LUN detection 



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: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarMatthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e113f29c

drivers/usb/storage/scsiglue.c

+15 −0
Original line number Diff line number Diff line
@@ -72,12 +72,27 @@ static const char* host_info(struct Scsi_Host *host) 


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;

}