ata: libata-scsi: Do not set the INFORMATION field twice for ATA PT

For ATA PASS-THROUGH + fixed format sense data + NCQ autosense
the INFORMATION sense data field is being written twice:

- 1st write: (redundant)
scsi_set_sense_information() sets the INFORMATION field to ATA LBA.
This is incorrect for ATA PASS-THROUGH.

- 2nd write: (correct)
ata_scsi_set_passthru_sense_fields() sets the INFORMATION field
to ATA ERROR/STATUS/DEVICE/COUNT(7:0) as per SAT spec.

There is no user-visible issue because second write overwrites
the incorrect data from the first write.

This patch eliminates the reduntant write by moving the INFORMATION
sense data field population logic to ata_scsi_qc_complete().

Signed-off-by: Igor Pylypiv <[email protected]>
Reviewed-by: Niklas Cassel <[email protected]>
Signed-off-by: Damien Le Moal <[email protected]>

Author: ipylypiv

drivers/ata/libata-sata.c

@@ -1659,8 +1659,6 @@ void ata_eh_analyze_ncq_error(struct ata_link *link)
 		if (ata_scsi_sense_is_valid(sense_key, asc, ascq)) {
 			ata_scsi_set_sense(dev, qc->scsicmd, sense_key, asc,
 					   ascq);
-			ata_scsi_set_sense_information(dev, qc->scsicmd,
-						       &qc->result_tf);
 			qc->flags |= ATA_QCFLAG_SENSE_VALID;
 		}
 	}

drivers/ata/libata-scsi.c

@@ -216,17 +216,21 @@ void ata_scsi_set_sense(struct ata_device *dev, struct scsi_cmnd *cmd,
 	scsi_build_sense(cmd, d_sense, sk, asc, ascq);
 }
 
-void ata_scsi_set_sense_information(struct ata_device *dev,
-				    struct scsi_cmnd *cmd,
-				    const struct ata_taskfile *tf)
+static void ata_scsi_set_sense_information(struct ata_queued_cmd *qc)
 {
 	u64 information;
 
-	information = ata_tf_read_block(tf, dev);
+	if (!(qc->flags & ATA_QCFLAG_RTF_FILLED)) {
+		ata_dev_dbg(qc->dev,
+			    "missing result TF: can't set INFORMATION sense field\n");
+		return;
+	}
+
+	information = ata_tf_read_block(&qc->result_tf, qc->dev);
 	if (information == U64_MAX)
 		return;
 
-	scsi_set_sense_information(cmd->sense_buffer,
+	scsi_set_sense_information(qc->scsicmd->sense_buffer,
 				   SCSI_SENSE_BUFFERSIZE, information);
 }
 
@@ -971,8 +975,7 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
  *	ata_gen_ata_sense - generate a SCSI fixed sense block
  *	@qc: Command that we are erroring out
  *
- *	Generate sense block for a failed ATA command @qc.  Descriptor
- *	format is used to accommodate LBA48 block address.
+ *	Generate sense block for a failed ATA command @qc.
  *
  *	LOCKING:
  *	None.
@@ -982,8 +985,6 @@ static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
 	struct ata_device *dev = qc->dev;
 	struct scsi_cmnd *cmd = qc->scsicmd;
 	struct ata_taskfile *tf = &qc->result_tf;
-	unsigned char *sb = cmd->sense_buffer;
-	u64 block;
 	u8 sense_key, asc, ascq;
 
 	if (ata_dev_disabled(dev)) {
@@ -1014,12 +1015,6 @@ static void ata_gen_ata_sense(struct ata_queued_cmd *qc)
 		ata_scsi_set_sense(dev, cmd, ABORTED_COMMAND, 0, 0);
 		return;
 	}
-
-	block = ata_tf_read_block(&qc->result_tf, dev);
-	if (block == U64_MAX)
-		return;
-
-	scsi_set_sense_information(sb, SCSI_SENSE_BUFFERSIZE, block);
 }
 
 void ata_scsi_sdev_config(struct scsi_device *sdev)
@@ -1679,8 +1674,10 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc)
 		ata_scsi_set_passthru_sense_fields(qc);
 		if (is_ck_cond_request)
 			set_status_byte(qc->scsicmd, SAM_STAT_CHECK_CONDITION);
-	} else if (is_error && !have_sense) {
-		ata_gen_ata_sense(qc);
+	} else if (is_error) {
+		if (!have_sense)
+			ata_gen_ata_sense(qc);
+		ata_scsi_set_sense_information(qc);
 	}
 
 	ata_qc_done(qc);

drivers/ata/libata.h

@@ -141,9 +141,6 @@ extern int ata_scsi_offline_dev(struct ata_device *dev);
 extern bool ata_scsi_sense_is_valid(u8 sk, u8 asc, u8 ascq);
 extern void ata_scsi_set_sense(struct ata_device *dev,
 			       struct scsi_cmnd *cmd, u8 sk, u8 asc, u8 ascq);
-extern void ata_scsi_set_sense_information(struct ata_device *dev,
-					   struct scsi_cmnd *cmd,
-					   const struct ata_taskfile *tf);
 extern void ata_scsi_media_change_notify(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);
 extern void ata_scsi_dev_rescan(struct work_struct *work);