diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 0b5d3a5b7eda..f70935cba173 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2539,7 +2539,7 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev,
 	ata_sg_init_one(qc, cmd->sense_buffer, sizeof(cmd->sense_buffer));
 	qc->dma_dir = DMA_FROM_DEVICE;
 
-	memset(&qc->cdb, 0, sizeof(ap->cdb_len));
+	memset(&qc->cdb, 0, ap->cdb_len);
 	qc->cdb[0] = REQUEST_SENSE;
 	qc->cdb[4] = SCSI_SENSE_BUFFERSIZE;
 
@@ -2811,6 +2811,7 @@ void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
 
 	/* call completion callback */
 	rc = qc->complete_fn(qc, drv_stat);
+	qc->flags &= ~ATA_QCFLAG_ACTIVE;
 
 	/* if callback indicates not to complete command (non-zero),
 	 * return immediately
@@ -3229,7 +3230,8 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
 			struct ata_queued_cmd *qc;
 
 			qc = ata_qc_from_tag(ap, ap->active_tag);
-			if (qc && (!(qc->tf.ctl & ATA_NIEN)))
+			if (qc && (!(qc->tf.ctl & ATA_NIEN)) &&
+			    (qc->flags & ATA_QCFLAG_ACTIVE))
 				handled |= ata_host_intr(ap, qc);
 		}
 	}