3 files changed, 23 insertions, 15 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 19ae3fa1cfcb..51cb9ca5519c 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -955,7 +955,6 @@ void ata_qc_complete_internal(struct ata_queued_cmd *qc)
 {
 	struct completion *waiting = qc->private_data;
 
-	qc->ap->ops->tf_read(qc->ap, &qc->tf);
 	complete(waiting);
 }
 
@@ -997,6 +996,7 @@ unsigned ata_exec_internal(struct ata_port *ap, struct ata_device *dev,
 	qc->tf = *tf;
 	if (cdb)
 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
+	qc->flags |= ATA_QCFLAG_RESULT_TF;
 	qc->dma_dir = dma_dir;
 	if (dma_dir != DMA_NONE) {
 		ata_sg_init_one(qc, buf, buflen);
@@ -1034,7 +1034,7 @@ unsigned ata_exec_internal(struct ata_port *ap, struct ata_device *dev,
 	/* finish up */
 	spin_lock_irqsave(&ap->host_set->lock, flags);
 
-	*tf = qc->tf;
+	*tf = qc->result_tf;
 	err_mask = qc->err_mask;
 
 	ata_qc_free(qc);
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index b0c83c28d578..ce90b6352a81 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -537,7 +537,7 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
 void ata_gen_ata_desc_sense(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *cmd = qc->scsicmd;
-	struct ata_taskfile *tf = &qc->tf;
+	struct ata_taskfile *tf = &qc->result_tf;
 	unsigned char *sb = cmd->sense_buffer;
 	unsigned char *desc = sb + 8;
 
@@ -608,7 +608,7 @@ void ata_gen_ata_desc_sense(struct ata_queued_cmd *qc)
 void ata_gen_fixed_sense(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *cmd = qc->scsicmd;
-	struct ata_taskfile *tf = &qc->tf;
+	struct ata_taskfile *tf = &qc->result_tf;
 	unsigned char *sb = cmd->sense_buffer;
 
 	memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
@@ -1199,14 +1199,11 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 	 */
 	if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
  	    ((cdb[2] & 0x20) || need_sense)) {
-		qc->ap->ops->tf_read(qc->ap, &qc->tf);
  		ata_gen_ata_desc_sense(qc);
 	} else {
 		if (!need_sense) {
 			cmd->result = SAM_STAT_GOOD;
 		} else {
-			qc->ap->ops->tf_read(qc->ap, &qc->tf);
-
 			/* TODO: decide which descriptor format to use
 			 * for 48b LBA devices and call that here
 			 * instead of the fixed desc, which is only
@@ -1217,10 +1214,8 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 		}
 	}
 
-	if (need_sense) {
-		/* The ata_gen_..._sense routines fill in tf */
-		ata_dump_status(qc->ap->id, &qc->tf);
-	}
+	if (need_sense)
+		ata_dump_status(qc->ap->id, &qc->result_tf);
 
 	qc->scsidone(cmd);
 
@@ -2004,7 +1999,6 @@ static void atapi_sense_complete(struct ata_queued_cmd *qc)
 		 * a sense descriptors, since that's only
 		 * correct for ATA, not ATAPI
 		 */
-		qc->ap->ops->tf_read(qc->ap, &qc->tf);
 		ata_gen_ata_desc_sense(qc);
 	}
 
@@ -2080,7 +2074,6 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
 		 * a sense descriptors, since that's only
 		 * correct for ATA, not ATAPI
 		 */
-		qc->ap->ops->tf_read(qc->ap, &qc->tf);
 		ata_gen_ata_desc_sense(qc);
 	} else {
 		u8 *scsicmd = cmd->cmnd;
@@ -2361,6 +2354,9 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 	 */
 	qc->nsect = cmd->bufflen / ATA_SECT_SIZE;
 
+	/* request result TF */
+	qc->flags |= ATA_QCFLAG_RESULT_TF;
+
 	return 0;
 
  invalid_fld:
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 0e1a3be39475..a4b8a419caad 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -162,7 +162,9 @@ enum {
 	ATA_QCFLAG_SINGLE	= (1 << 2), /* no s/g, just a single buffer */
 	ATA_QCFLAG_DMAMAP	= ATA_QCFLAG_SG | ATA_QCFLAG_SINGLE,
 	ATA_QCFLAG_IO		= (1 << 3), /* standard IO command */
-	ATA_QCFLAG_EH_SCHEDULED = (1 << 4), /* EH scheduled */
+	ATA_QCFLAG_RESULT_TF	= (1 << 4), /* result TF requested */
+
+	ATA_QCFLAG_EH_SCHEDULED = (1 << 16), /* EH scheduled */
 
 	/* host set flags */
 	ATA_HOST_SIMPLEX	= (1 << 0),	/* Host is simplex, one DMA channel per host_set only */
@@ -343,7 +345,7 @@ struct ata_queued_cmd {
 	struct scatterlist	*__sg;
 
 	unsigned int		err_mask;
-
+	struct ata_taskfile	result_tf;
 	ata_qc_cb_t		complete_fn;
 
 	void			*private_data;
@@ -824,6 +826,10 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
 	qc->err_mask = 0;
 
 	ata_tf_init(qc->ap, &qc->tf, qc->dev->devno);
+
+	/* init result_tf such that it indicates normal completion */
+	qc->result_tf.command = ATA_DRDY;
+	qc->result_tf.feature = 0;
 }
 
 /**
@@ -839,9 +845,15 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
  */
 static inline void ata_qc_complete(struct ata_queued_cmd *qc)
 {
+	struct ata_port *ap = qc->ap;
+
 	if (unlikely(qc->flags & ATA_QCFLAG_EH_SCHEDULED))
 		return;
 
+	/* read result TF if failed or requested */
+	if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
+		ap->ops->tf_read(ap, &qc->result_tf);
+
 	__ata_qc_complete(qc);
 }