Merge of rsync://rsync.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev.git

drivers/scsi/libata-core.c

···
 	unsigned long timeout = jiffies + (HZ * 5);
 
 	if (ap->flags & ATA_FLAG_SATA_RESET) {
-		scr_write(ap, SCR_CONTROL, 0x301); /* issue phy wake/reset */
-		scr_read(ap, SCR_STATUS);	/* dummy read; flush */
+		/* issue phy wake/reset */
+		scr_write_flush(ap, SCR_CONTROL, 0x301);
 		udelay(400);			/* FIXME: a guess */
 	}
-	scr_write(ap, SCR_CONTROL, 0x300);	/* issue phy wake/clear reset */
+	scr_write_flush(ap, SCR_CONTROL, 0x300); /* phy wake/clear reset */
 
 	/* wait for phy to become ready, if necessary */
 	do {
···
 	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;
 
···
 
 	/* 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
···
 			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);
 		}
 	}

drivers/scsi/libata-scsi.c

···
 		 */
 		if ((dev->flags & ATA_DFLAG_LBA48) &&
 		    ((dev->flags & ATA_DFLAG_LOCK_SECTORS) == 0)) {
-			sdev->host->max_sectors = 2048;
+			/*
+			 * do not overwrite sdev->host->max_sectors, since
+			 * other drives on this host may not support LBA48
+			 */
 			blk_queue_max_sectors(sdev->request_queue, 2048);
 		}
 	}

include/linux/libata.h

···
 	ap->ops->scr_write(ap, reg, val);
 }
 
+static inline void scr_write_flush(struct ata_port *ap, unsigned int reg, 
+				   u32 val)
+{
+	ap->ops->scr_write(ap, reg, val);
+	(void) ap->ops->scr_read(ap, reg);
+}
+
 static inline unsigned int sata_dev_present(struct ata_port *ap)
 {
 	return ((scr_read(ap, SCR_STATUS) & 0xf) == 0x3) ? 1 : 0;