scsi: mac_scsi: Treat Last Byte Sent time-out as failure

A system bus error during a PDMA send operation can result in bytes being
lost. Theoretically that could cause the target to remain in DATA OUT phase
and the initiator (expecting a phase change) would time-out waiting for the
Last Byte Sent flag. Should that happen, fail the transfer so the core
driver will stop using PDMA with this target.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c
index 8fbec17..658a719 100644 (file)
--- a/drivers/scsi/mac_scsi.c
+++ b/drivers/scsi/mac_scsi.c
@@ -360,9 +360,12 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata,
                if (hostdata->pdma_residual == 0) {
                        if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
                                                  TCR_LAST_BYTE_SENT,
-                                                 TCR_LAST_BYTE_SENT, HZ / 64) < 0)
+                                                 TCR_LAST_BYTE_SENT,
+                                                 HZ / 64) < 0) {
                                scmd_printk(KERN_ERR, hostdata->connected,
                                            "%s: Last Byte Sent timeout\n", __func__);
+                               result = -1;
+                       }
                        goto out;
                }