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>

2 files changed, 14 insertions, 8 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 5440cd050268..6b3350f71a89 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -2213,28 +2213,34 @@ static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid,
                 spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
 
                 if (SCpnt) {
-                        if (STATUS_TEST_RS(sb->ORB_offset_hi_misc))
+                        u32 h = sb->ORB_offset_hi_misc;
+                        u32 r = STATUS_GET_RESP(h);
+
+                        if (r != RESP_STATUS_REQUEST_COMPLETE) {
+                                SBP2_WARN("resp 0x%x, sbp_status 0x%x",
+                                          r, STATUS_GET_SBP_STATUS(h));
                                 scsi_status =
+                                        r == RESP_STATUS_TRANSPORT_FAILURE ?
+                                        SBP2_SCSI_STATUS_BUSY :
                                         SBP2_SCSI_STATUS_COMMAND_TERMINATED;
+                        }
                         /*
                          * See if the target stored any scsi status information.
                          */
-                        if (STATUS_GET_LEN(sb->ORB_offset_hi_misc) > 1) {
+                        if (STATUS_GET_LEN(h) > 1) {
                                 SBP2_DEBUG("CHECK CONDITION");
                                 scsi_status = sbp2_status_to_sense_data(
                                         (unchar *)sb, SCpnt->sense_buffer);
                         }
-
                         /*
                          * Check to see if the dead bit is set. If so, we'll
                          * have to initiate a fetch agent reset.
                          */
-                        if (STATUS_TEST_D(sb->ORB_offset_hi_misc)) {
+                        if (STATUS_TEST_DEAD(h)) {
                                 SBP2_DEBUG("Dead bit set - "
                                            "initiating fetch agent reset");
                                 sbp2_agent_reset(scsi_id, 0);
                         }
-
                         SBP2_ORB_DEBUG("completing command orb %p", &command->command_orb);
                 }
 
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index 1c9fe422cf4c..34c52bf4fa34 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -181,11 +181,11 @@ struct sbp2_unrestricted_page_table {
 #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)