ieee1394: sbp2: better handling of transport errors

If the target signals a transport failure via status block, complete the
request with DID_BUSY to indicate to the SCSI subsystem that the command
may succeed when retried.

Also log diagnostic information if the status block shows a transport
related problem.  It may point to hardware faults.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index 1c9fe42..34c52bf 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -181,11 +181,11 @@
 #define SBP2_SCSI_STATUS_SELECTION_TIMEOUT	0xff
 
 #define STATUS_GET_SRC(value)			(((value) >> 30) & 0x3)
+#define STATUS_GET_RESP(value)			(((value) >> 28) & 0x3)
 #define STATUS_GET_LEN(value)			(((value) >> 24) & 0x7)
+#define STATUS_GET_SBP_STATUS(value)		(((value) >> 16) & 0xff)
 #define STATUS_GET_ORB_OFFSET_HI(value)		((value) & 0x0000ffff)
-#define STATUS_TEST_D(value)			((value) & 0x08000000)
-/* test 'resp' | 'sbp2_status' */
-#define STATUS_TEST_RS(value)			((value) & 0x30ff0000)
+#define STATUS_TEST_DEAD(value)			((value) & 0x08000000)
 /* test 'resp' | 'dead' | 'sbp2_status' */
 #define STATUS_TEST_RDS(value)			((value) & 0x38ff0000)