[SCSI] SPI transport class, don't negotiate options not supported

At the moment, the transport class blindly tries to set things like
QAS and IU, even if the drive won't support them.  It's best not to
annoy the devices like this and instead only set what the drive says
is actually supported.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_spi.c

@@ -795,7 +795,8 @@ spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
 	}
 
 	/* test width */
-	if (i->f->set_width && spi_max_width(starget) && sdev->wdtr) {
+	if (i->f->set_width && spi_max_width(starget) &&
+	    scsi_device_wide(sdev)) {
 		i->f->set_width(starget, 1);
 
 		if (spi_dv_device_compare_inquiry(sreq, buffer,
@@ -811,14 +812,14 @@ spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
 		return;
 
 	/* device can't handle synchronous */
-	if (!sdev->ppr && !sdev->sdtr)
+	if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev))
 		return;
 
 	/* see if the device has an echo buffer.  If it does we can
 	 * do the SPI pattern write tests */
 
 	len = 0;
-	if (sdev->ppr)
+	if (scsi_device_dt(sdev))
 		len = spi_dv_device_get_echo_buffer(sreq, buffer);
 
  retry:
@@ -828,9 +829,11 @@ spi_dv_device_internal(struct scsi_request *sreq, u8 *buffer)
 	DV_SET(period, spi_min_period(starget));
 	/* try QAS requests; this should be harmless to set if the
 	 * target supports it */
-	DV_SET(qas, 1);
+	if (scsi_device_qas(sdev))
+		DV_SET(qas, 1);
 	/* Also try IU transfers */
-	DV_SET(iu, 1);
+	if (scsi_device_ius(sdev))
+		DV_SET(iu, 1);
 	if (spi_min_period(starget) < 9) {
 		/* This u320 (or u640). Ignore the coupled parameters
 		 * like DT and IU, but set the optional ones */