]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/scsi/libata-core.c
Merge branch 'upstream'
[linux-2.6-omap-h63xx.git] / drivers / scsi / libata-core.c
index 966be3034bf02ae243b76d41340f7e4898c5f45f..56537293ad4139661f8583ce2c41c71c5182e238 100644 (file)
@@ -1305,11 +1305,19 @@ static int ata_dev_configure(struct ata_port *ap, struct ata_device *dev,
                                       dev->cylinders, dev->heads, dev->sectors);
                }
 
+               if (dev->id[59] & 0x100) {
+                       dev->multi_count = dev->id[59] & 0xff;
+                       DPRINTK("ata%u: dev %u multi count %u\n",
+                               ap->id, dev->devno, dev->multi_count);
+               }
+
                dev->cdb_len = 16;
        }
 
        /* ATAPI-specific feature tests */
        else if (dev->class == ATA_DEV_ATAPI) {
+               char *cdb_intr_string = "";
+
                rc = atapi_cdb_len(id);
                if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
                        printk(KERN_WARNING "ata%u: unsupported CDB len\n", ap->id);
@@ -1318,10 +1326,16 @@ static int ata_dev_configure(struct ata_port *ap, struct ata_device *dev,
                }
                dev->cdb_len = (unsigned int) rc;
 
+               if (ata_id_cdb_intr(dev->id)) {
+                       dev->flags |= ATA_DFLAG_CDB_INTR;
+                       cdb_intr_string = ", CDB intr";
+               }
+
                /* print device info to dmesg */
                if (print_info)
-                       printk(KERN_INFO "ata%u: dev %u ATAPI, max %s\n",
-                              ap->id, dev->devno, ata_mode_string(xfer_mask));
+                       printk(KERN_INFO "ata%u: dev %u ATAPI, max %s%s\n",
+                              ap->id, dev->devno, ata_mode_string(xfer_mask),
+                              cdb_intr_string);
        }
 
        ap->host->max_cmd_len = 0;
@@ -3167,6 +3181,15 @@ int ata_check_atapi_dma(struct ata_queued_cmd *qc)
        if (ap->ops->check_atapi_dma)
                rc = ap->ops->check_atapi_dma(qc);
 
+       /* We don't support polling DMA.
+        * Use PIO if the LLDD handles only interrupts in
+        * the HSM_ST_LAST state and the ATAPI device
+        * generates CDB interrupts.
+        */
+       if ((ap->flags & ATA_FLAG_PIO_POLLING) &&
+           (qc->dev->flags & ATA_DFLAG_CDB_INTR))
+               rc = 1;
+
        return rc;
 }
 /**
@@ -3409,111 +3432,11 @@ void ata_poll_qc_complete(struct ata_queued_cmd *qc)
        unsigned long flags;
 
        spin_lock_irqsave(&ap->host_set->lock, flags);
-       ap->flags &= ~ATA_FLAG_NOINTR;
        ata_irq_on(ap);
        ata_qc_complete(qc);
        spin_unlock_irqrestore(&ap->host_set->lock, flags);
 }
 
-/**
- *     ata_pio_poll - poll using PIO, depending on current state
- *     @qc: qc in progress
- *
- *     LOCKING:
- *     None.  (executing in kernel thread context)
- *
- *     RETURNS:
- *     timeout value to use
- */
-static unsigned long ata_pio_poll(struct ata_queued_cmd *qc)
-{
-       struct ata_port *ap = qc->ap;
-       u8 status;
-       unsigned int poll_state = HSM_ST_UNKNOWN;
-       unsigned int reg_state = HSM_ST_UNKNOWN;
-
-       switch (ap->hsm_task_state) {
-       case HSM_ST:
-       case HSM_ST_POLL:
-               poll_state = HSM_ST_POLL;
-               reg_state = HSM_ST;
-               break;
-       case HSM_ST_LAST:
-       case HSM_ST_LAST_POLL:
-               poll_state = HSM_ST_LAST_POLL;
-               reg_state = HSM_ST_LAST;
-               break;
-       default:
-               BUG();
-               break;
-       }
-
-       status = ata_chk_status(ap);
-       if (status & ATA_BUSY) {
-               if (time_after(jiffies, ap->pio_task_timeout)) {
-                       qc->err_mask |= AC_ERR_TIMEOUT;
-                       ap->hsm_task_state = HSM_ST_TMOUT;
-                       return 0;
-               }
-               ap->hsm_task_state = poll_state;
-               return ATA_SHORT_PAUSE;
-       }
-
-       ap->hsm_task_state = reg_state;
-       return 0;
-}
-
-/**
- *     ata_pio_complete - check if drive is busy or idle
- *     @qc: qc to complete
- *
- *     LOCKING:
- *     None.  (executing in kernel thread context)
- *
- *     RETURNS:
- *     Non-zero if qc completed, zero otherwise.
- */
-static int ata_pio_complete(struct ata_queued_cmd *qc)
-{
-       struct ata_port *ap = qc->ap;
-       u8 drv_stat;
-
-       /*
-        * This is purely heuristic.  This is a fast path.  Sometimes when
-        * we enter, BSY will be cleared in a chk-status or two.  If not,
-        * the drive is probably seeking or something.  Snooze for a couple
-        * msecs, then chk-status again.  If still busy, fall back to
-        * HSM_ST_POLL state.
-        */
-       drv_stat = ata_busy_wait(ap, ATA_BUSY, 10);
-       if (drv_stat & ATA_BUSY) {
-               msleep(2);
-               drv_stat = ata_busy_wait(ap, ATA_BUSY, 10);
-               if (drv_stat & ATA_BUSY) {
-                       ap->hsm_task_state = HSM_ST_LAST_POLL;
-                       ap->pio_task_timeout = jiffies + ATA_TMOUT_PIO;
-                       return 0;
-               }
-       }
-
-       drv_stat = ata_wait_idle(ap);
-       if (!ata_ok(drv_stat)) {
-               qc->err_mask |= __ac_err_mask(drv_stat);
-               ap->hsm_task_state = HSM_ST_ERR;
-               return 0;
-       }
-
-       ap->hsm_task_state = HSM_ST_IDLE;
-
-       WARN_ON(qc->err_mask);
-       ata_poll_qc_complete(qc);
-
-       /* another command may start at this point */
-
-       return 1;
-}
-
-
 /**
  *     swap_buf_le16 - swap halves of 16-bit words in place
  *     @buf:  Buffer to swap
@@ -3682,7 +3605,23 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
        page = nth_page(page, (offset >> PAGE_SHIFT));
        offset %= PAGE_SIZE;
 
-       buf = kmap(page) + offset;
+       DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
+
+       if (PageHighMem(page)) {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               buf = kmap_atomic(page, KM_IRQ0);
+
+               /* do the actual data transfer */
+               ata_data_xfer(ap, buf + offset, ATA_SECT_SIZE, do_write);
+
+               kunmap_atomic(buf, KM_IRQ0);
+               local_irq_restore(flags);
+       } else {
+               buf = page_address(page);
+               ata_data_xfer(ap, buf + offset, ATA_SECT_SIZE, do_write);
+       }
 
        qc->cursect++;
        qc->cursg_ofs++;
@@ -3691,14 +3630,68 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
                qc->cursg++;
                qc->cursg_ofs = 0;
        }
+}
 
-       DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
+/**
+ *     ata_pio_sectors - Transfer one or many 512-byte sectors.
+ *     @qc: Command on going
+ *
+ *     Transfer one or many ATA_SECT_SIZE of data from/to the 
+ *     ATA device for the DRQ request.
+ *
+ *     LOCKING:
+ *     Inherited from caller.
+ */
+
+static void ata_pio_sectors(struct ata_queued_cmd *qc)
+{
+       if (is_multi_taskfile(&qc->tf)) {
+               /* READ/WRITE MULTIPLE */
+               unsigned int nsect;
+
+               WARN_ON(qc->dev->multi_count == 0);
+
+               nsect = min(qc->nsect - qc->cursect, qc->dev->multi_count);
+               while (nsect--)
+                       ata_pio_sector(qc);
+       } else
+               ata_pio_sector(qc);
+}
+
+/**
+ *     atapi_send_cdb - Write CDB bytes to hardware
+ *     @ap: Port to which ATAPI device is attached.
+ *     @qc: Taskfile currently active
+ *
+ *     When device has indicated its readiness to accept
+ *     a CDB, this function is called.  Send the CDB.
+ *
+ *     LOCKING:
+ *     caller.
+ */
 
-       /* do the actual data transfer */
-       do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
-       ata_data_xfer(ap, buf, ATA_SECT_SIZE, do_write);
+static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
+{
+       /* send SCSI cdb */
+       DPRINTK("send cdb\n");
+       WARN_ON(qc->dev->cdb_len < 12);
+
+       ata_data_xfer(ap, qc->cdb, qc->dev->cdb_len, 1);
+       ata_altstatus(ap); /* flush */
 
-       kunmap(page);
+       switch (qc->tf.protocol) {
+       case ATA_PROT_ATAPI:
+               ap->hsm_task_state = HSM_ST;
+               break;
+       case ATA_PROT_ATAPI_NODATA:
+               ap->hsm_task_state = HSM_ST_LAST;
+               break;
+       case ATA_PROT_ATAPI_DMA:
+               ap->hsm_task_state = HSM_ST_LAST;
+               /* initiate bmdma */
+               ap->ops->bmdma_start(qc);
+               break;
+       }
 }
 
 /**
@@ -3764,7 +3757,23 @@ next_sg:
        /* don't cross page boundaries */
        count = min(count, (unsigned int)PAGE_SIZE - offset);
 
-       buf = kmap(page) + offset;
+       DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
+
+       if (PageHighMem(page)) {
+               unsigned long flags;
+
+               local_irq_save(flags);
+               buf = kmap_atomic(page, KM_IRQ0);
+
+               /* do the actual data transfer */
+               ata_data_xfer(ap, buf + offset, count, do_write);
+
+               kunmap_atomic(buf, KM_IRQ0);
+               local_irq_restore(flags);
+       } else {
+               buf = page_address(page);
+               ata_data_xfer(ap, buf + offset, count, do_write);
+       }
 
        bytes -= count;
        qc->curbytes += count;
@@ -3775,13 +3784,6 @@ next_sg:
                qc->cursg_ofs = 0;
        }
 
-       DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
-
-       /* do the actual data transfer */
-       ata_data_xfer(ap, buf, count, do_write);
-
-       kunmap(page);
-
        if (bytes)
                goto next_sg;
 }
@@ -3818,6 +3820,8 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
        if (do_write != i_write)
                goto err_out;
 
+       VPRINTK("ata%u: xfering %d bytes\n", ap->id, bytes);
+
        __atapi_pio_bytes(qc, bytes);
 
        return;
@@ -3830,187 +3834,297 @@ err_out:
 }
 
 /**
- *     ata_pio_block - start PIO on a block
- *     @qc: qc to transfer block for
+ *     ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
+ *     @ap: the target ata_port
+ *     @qc: qc on going
  *
- *     LOCKING:
- *     None.  (executing in kernel thread context)
+ *     RETURNS:
+ *     1 if ok in workqueue, 0 otherwise.
  */
-static void ata_pio_block(struct ata_queued_cmd *qc)
+
+static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
 {
-       struct ata_port *ap = qc->ap;
-       u8 status;
+       if (qc->tf.flags & ATA_TFLAG_POLLING)
+               return 1;
 
-       /*
-        * This is purely heuristic.  This is a fast path.
-        * Sometimes when we enter, BSY will be cleared in
-        * a chk-status or two.  If not, the drive is probably seeking
-        * or something.  Snooze for a couple msecs, then
-        * chk-status again.  If still busy, fall back to
-        * HSM_ST_POLL state.
-        */
-       status = ata_busy_wait(ap, ATA_BUSY, 5);
-       if (status & ATA_BUSY) {
-               msleep(2);
-               status = ata_busy_wait(ap, ATA_BUSY, 10);
-               if (status & ATA_BUSY) {
-                       ap->hsm_task_state = HSM_ST_POLL;
-                       ap->pio_task_timeout = jiffies + ATA_TMOUT_PIO;
-                       return;
-               }
-       }
+       if (ap->hsm_task_state == HSM_ST_FIRST) {
+               if (qc->tf.protocol == ATA_PROT_PIO &&
+                   (qc->tf.flags & ATA_TFLAG_WRITE))
+                   return 1;
 
-       /* check error */
-       if (status & (ATA_ERR | ATA_DF)) {
-               qc->err_mask |= AC_ERR_DEV;
-               ap->hsm_task_state = HSM_ST_ERR;
-               return;
+               if (is_atapi_taskfile(&qc->tf) &&
+                   !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
+                       return 1;
        }
 
-       /* transfer data if any */
-       if (is_atapi_taskfile(&qc->tf)) {
-               /* DRQ=0 means no more data to transfer */
-               if ((status & ATA_DRQ) == 0) {
-                       ap->hsm_task_state = HSM_ST_LAST;
-                       return;
-               }
+       return 0;
+}
 
-               atapi_pio_bytes(qc);
-       } else {
-               /* handle BSY=0, DRQ=0 as error */
-               if ((status & ATA_DRQ) == 0) {
+/**
+ *     ata_hsm_move - move the HSM to the next state.
+ *     @ap: the target ata_port
+ *     @qc: qc on going
+ *     @status: current device status
+ *     @in_wq: 1 if called from workqueue, 0 otherwise
+ *
+ *     RETURNS:
+ *     1 when poll next status needed, 0 otherwise.
+ */
+
+static int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
+                        u8 status, int in_wq)
+{
+       unsigned long flags = 0;
+       int poll_next;
+
+       WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
+
+       /* Make sure ata_qc_issue_prot() does not throw things
+        * like DMA polling into the workqueue. Notice that
+        * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
+        */
+       WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
+
+fsm_start:
+       DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
+               ap->id, qc->tf.protocol, ap->hsm_task_state, status);
+
+       switch (ap->hsm_task_state) {
+       case HSM_ST_FIRST:
+               /* Send first data block or PACKET CDB */
+
+               /* If polling, we will stay in the work queue after
+                * sending the data. Otherwise, interrupt handler
+                * takes over after sending the data.
+                */
+               poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
+
+               /* check device status */
+               if (unlikely((status & (ATA_BUSY | ATA_DRQ)) != ATA_DRQ)) {
+                       /* Wrong status. Let EH handle this */
                        qc->err_mask |= AC_ERR_HSM;
                        ap->hsm_task_state = HSM_ST_ERR;
-                       return;
+                       goto fsm_start;
                }
 
-               ata_pio_sector(qc);
-       }
-}
+               /* Device should not ask for data transfer (DRQ=1)
+                * when it finds something wrong.
+                * We ignore DRQ here and stop the HSM by
+                * changing hsm_task_state to HSM_ST_ERR and
+                * let the EH abort the command or reset the device.
+                */
+               if (unlikely(status & (ATA_ERR | ATA_DF))) {
+                       printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
+                              ap->id, status);
+                       qc->err_mask |= AC_ERR_DEV;
+                       ap->hsm_task_state = HSM_ST_ERR;
+                       goto fsm_start;
+               }
 
-static void ata_pio_error(struct ata_queued_cmd *qc)
-{
-       struct ata_port *ap = qc->ap;
+               /* Send the CDB (atapi) or the first data block (ata pio out).
+                * During the state transition, interrupt handler shouldn't
+                * be invoked before the data transfer is complete and
+                * hsm_task_state is changed. Hence, the following locking.
+                */
+               if (in_wq)
+                       spin_lock_irqsave(&ap->host_set->lock, flags);
 
-       if (qc->tf.command != ATA_CMD_PACKET)
-               printk(KERN_WARNING "ata%u: dev %u PIO error\n",
-                      ap->id, qc->dev->devno);
+               if (qc->tf.protocol == ATA_PROT_PIO) {
+                       /* PIO data out protocol.
+                        * send first data block.
+                        */
 
-       /* make sure qc->err_mask is available to
-        * know what's wrong and recover
-        */
-       WARN_ON(qc->err_mask == 0);
+                       /* ata_pio_sectors() might change the state
+                        * to HSM_ST_LAST. so, the state is changed here
+                        * before ata_pio_sectors().
+                        */
+                       ap->hsm_task_state = HSM_ST;
+                       ata_pio_sectors(qc);
+                       ata_altstatus(ap); /* flush */
+               } else
+                       /* send CDB */
+                       atapi_send_cdb(ap, qc);
+
+               if (in_wq)
+                       spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+               /* if polling, ata_pio_task() handles the rest.
+                * otherwise, interrupt handler takes over from here.
+                */
+               break;
 
-       ap->hsm_task_state = HSM_ST_IDLE;
+       case HSM_ST:
+               /* complete command or read/write the data register */
+               if (qc->tf.protocol == ATA_PROT_ATAPI) {
+                       /* ATAPI PIO protocol */
+                       if ((status & ATA_DRQ) == 0) {
+                               /* no more data to transfer */
+                               ap->hsm_task_state = HSM_ST_LAST;
+                               goto fsm_start;
+                       }
 
-       ata_poll_qc_complete(qc);
-}
+                       /* Device should not ask for data transfer (DRQ=1)
+                        * when it finds something wrong.
+                        * We ignore DRQ here and stop the HSM by
+                        * changing hsm_task_state to HSM_ST_ERR and
+                        * let the EH abort the command or reset the device.
+                        */
+                       if (unlikely(status & (ATA_ERR | ATA_DF))) {
+                               printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
+                                      ap->id, status);
+                               qc->err_mask |= AC_ERR_DEV;
+                               ap->hsm_task_state = HSM_ST_ERR;
+                               goto fsm_start;
+                       }
 
-static void ata_pio_task(void *_data)
-{
-       struct ata_queued_cmd *qc = _data;
-       struct ata_port *ap = qc->ap;
-       unsigned long timeout;
-       int qc_completed;
+                       atapi_pio_bytes(qc);
 
-fsm_start:
-       timeout = 0;
-       qc_completed = 0;
+                       if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
+                               /* bad ireason reported by device */
+                               goto fsm_start;
 
-       switch (ap->hsm_task_state) {
-       case HSM_ST_IDLE:
-               return;
+               } else {
+                       /* ATA PIO protocol */
+                       if (unlikely((status & ATA_DRQ) == 0)) {
+                               /* handle BSY=0, DRQ=0 as error */
+                               qc->err_mask |= AC_ERR_HSM;
+                               ap->hsm_task_state = HSM_ST_ERR;
+                               goto fsm_start;
+                       }
 
-       case HSM_ST:
-               ata_pio_block(qc);
+                       /* For PIO reads, some devices may ask for
+                        * data transfer (DRQ=1) alone with ERR=1.
+                        * We respect DRQ here and transfer one
+                        * block of junk data before changing the
+                        * hsm_task_state to HSM_ST_ERR.
+                        *
+                        * For PIO writes, ERR=1 DRQ=1 doesn't make
+                        * sense since the data block has been
+                        * transferred to the device.
+                        */
+                       if (unlikely(status & (ATA_ERR | ATA_DF))) {
+                               /* data might be corrputed */
+                               qc->err_mask |= AC_ERR_DEV;
+
+                               if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
+                                       ata_pio_sectors(qc);
+                                       ata_altstatus(ap);
+                                       status = ata_wait_idle(ap);
+                               }
+
+                               /* ata_pio_sectors() might change the
+                                * state to HSM_ST_LAST. so, the state
+                                * is changed after ata_pio_sectors().
+                                */
+                               ap->hsm_task_state = HSM_ST_ERR;
+                               goto fsm_start;
+                       }
+
+                       ata_pio_sectors(qc);
+
+                       if (ap->hsm_task_state == HSM_ST_LAST &&
+                           (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
+                               /* all data read */
+                               ata_altstatus(ap);
+                               status = ata_wait_idle(ap);
+                               goto fsm_start;
+                       }
+               }
+
+               ata_altstatus(ap); /* flush */
+               poll_next = 1;
                break;
 
        case HSM_ST_LAST:
-               qc_completed = ata_pio_complete(qc);
-               break;
+               if (unlikely(!ata_ok(status))) {
+                       qc->err_mask |= __ac_err_mask(status);
+                       ap->hsm_task_state = HSM_ST_ERR;
+                       goto fsm_start;
+               }
+
+               /* no more data to transfer */
+               DPRINTK("ata%u: command complete, drv_stat 0x%x\n",
+                       ap->id, status);
+
+               WARN_ON(qc->err_mask);
+
+               ap->hsm_task_state = HSM_ST_IDLE;
 
-       case HSM_ST_POLL:
-       case HSM_ST_LAST_POLL:
-               timeout = ata_pio_poll(qc);
+               /* complete taskfile transaction */
+               if (in_wq)
+                       ata_poll_qc_complete(qc);
+               else
+                       ata_qc_complete(qc);
+
+               poll_next = 0;
                break;
 
-       case HSM_ST_TMOUT:
        case HSM_ST_ERR:
-               ata_pio_error(qc);
-               return;
+               if (qc->tf.command != ATA_CMD_PACKET)
+                       printk(KERN_ERR "ata%u: command error, drv_stat 0x%x\n",
+                              ap->id, status);
+
+               /* make sure qc->err_mask is available to
+                * know what's wrong and recover
+                */
+               WARN_ON(qc->err_mask == 0);
+
+               ap->hsm_task_state = HSM_ST_IDLE;
+
+               /* complete taskfile transaction */
+               if (in_wq)
+                       ata_poll_qc_complete(qc);
+               else
+                       ata_qc_complete(qc);
+
+               poll_next = 0;
+               break;
+       default:
+               poll_next = 0;
+               BUG();
        }
 
-       if (timeout)
-               ata_port_queue_task(ap, ata_pio_task, qc, timeout);
-       else if (!qc_completed)
-               goto fsm_start;
+       return poll_next;
 }
 
-/**
- *     atapi_packet_task - Write CDB bytes to hardware
- *     @_data: qc in progress
- *
- *     When device has indicated its readiness to accept
- *     a CDB, this function is called.  Send the CDB.
- *     If DMA is to be performed, exit immediately.
- *     Otherwise, we are in polling mode, so poll
- *     status under operation succeeds or fails.
- *
- *     LOCKING:
- *     Kernel thread context (may sleep)
- */
-static void atapi_packet_task(void *_data)
+static void ata_pio_task(void *_data)
 {
        struct ata_queued_cmd *qc = _data;
        struct ata_port *ap = qc->ap;
        u8 status;
+       int poll_next;
 
-       /* sleep-wait for BSY to clear */
-       DPRINTK("busy wait\n");
-       if (ata_busy_sleep(ap, ATA_TMOUT_CDB_QUICK, ATA_TMOUT_CDB)) {
-               qc->err_mask |= AC_ERR_TIMEOUT;
-               goto err_out;
-       }
-
-       /* make sure DRQ is set */
-       status = ata_chk_status(ap);
-       if ((status & (ATA_BUSY | ATA_DRQ)) != ATA_DRQ) {
-               qc->err_mask |= AC_ERR_HSM;
-               goto err_out;
-       }
-
-       /* send SCSI cdb */
-       DPRINTK("send cdb\n");
-       WARN_ON(qc->dev->cdb_len < 12);
-
-       if (qc->tf.protocol == ATA_PROT_ATAPI_DMA ||
-           qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
-               unsigned long flags;
+fsm_start:
+       WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
 
-               /* Once we're done issuing command and kicking bmdma,
-                * irq handler takes over.  To not lose irq, we need
-                * to clear NOINTR flag before sending cdb, but
-                * interrupt handler shouldn't be invoked before we're
-                * finished.  Hence, the following locking.
-                */
-               spin_lock_irqsave(&ap->host_set->lock, flags);
-               ap->flags &= ~ATA_FLAG_NOINTR;
-               ata_data_xfer(ap, qc->cdb, qc->dev->cdb_len, 1);
-               if (qc->tf.protocol == ATA_PROT_ATAPI_DMA)
-                       ap->ops->bmdma_start(qc);       /* initiate bmdma */
-               spin_unlock_irqrestore(&ap->host_set->lock, flags);
-       } else {
-               ata_data_xfer(ap, qc->cdb, qc->dev->cdb_len, 1);
+       qc = ata_qc_from_tag(ap, ap->active_tag);
+       WARN_ON(qc == NULL);
 
-               /* PIO commands are handled by polling */
-               ap->hsm_task_state = HSM_ST;
-               ata_port_queue_task(ap, ata_pio_task, qc, 0);
+       /*
+        * This is purely heuristic.  This is a fast path.
+        * Sometimes when we enter, BSY will be cleared in
+        * a chk-status or two.  If not, the drive is probably seeking
+        * or something.  Snooze for a couple msecs, then
+        * chk-status again.  If still busy, queue delayed work.
+        */
+       status = ata_busy_wait(ap, ATA_BUSY, 5);
+       if (status & ATA_BUSY) {
+               msleep(2);
+               status = ata_busy_wait(ap, ATA_BUSY, 10);
+               if (status & ATA_BUSY) {
+                       ata_port_queue_task(ap, ata_pio_task, ap, ATA_SHORT_PAUSE);
+                       return;
+               }
        }
 
-       return;
+       /* move the HSM */
+       poll_next = ata_hsm_move(ap, qc, status, 1);
 
-err_out:
-       ata_poll_qc_complete(qc);
+       /* another command or interrupt handler
+        * may be running at this point.
+        */
+       if (poll_next)
+               goto fsm_start;
 }
 
 /**
@@ -4200,43 +4314,105 @@ unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
 {
        struct ata_port *ap = qc->ap;
 
+       /* Use polling pio if the LLD doesn't handle
+        * interrupt driven pio and atapi CDB interrupt.
+        */
+       if (ap->flags & ATA_FLAG_PIO_POLLING) {
+               switch (qc->tf.protocol) {
+               case ATA_PROT_PIO:
+               case ATA_PROT_ATAPI:
+               case ATA_PROT_ATAPI_NODATA:
+                       qc->tf.flags |= ATA_TFLAG_POLLING;
+                       break;
+               case ATA_PROT_ATAPI_DMA:
+                       if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
+                               /* see ata_check_atapi_dma() */
+                               BUG();
+                       break;
+               default:
+                       break;
+               }
+       }
+
+       /* select the device */
        ata_dev_select(ap, qc->dev->devno, 1, 0);
 
+       /* start the command */
        switch (qc->tf.protocol) {
        case ATA_PROT_NODATA:
+               if (qc->tf.flags & ATA_TFLAG_POLLING)
+                       ata_qc_set_polling(qc);
+
                ata_tf_to_host(ap, &qc->tf);
+               ap->hsm_task_state = HSM_ST_LAST;
+
+               if (qc->tf.flags & ATA_TFLAG_POLLING)
+                       ata_port_queue_task(ap, ata_pio_task, ap, 0);
+
                break;
 
        case ATA_PROT_DMA:
+               WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+
                ap->ops->tf_load(ap, &qc->tf);   /* load tf registers */
                ap->ops->bmdma_setup(qc);           /* set up bmdma */
                ap->ops->bmdma_start(qc);           /* initiate bmdma */
+               ap->hsm_task_state = HSM_ST_LAST;
                break;
 
-       case ATA_PROT_PIO: /* load tf registers, initiate polling pio */
-               ata_qc_set_polling(qc);
-               ata_tf_to_host(ap, &qc->tf);
-               ap->hsm_task_state = HSM_ST;
-               ata_port_queue_task(ap, ata_pio_task, qc, 0);
-               break;
+       case ATA_PROT_PIO:
+               if (qc->tf.flags & ATA_TFLAG_POLLING)
+                       ata_qc_set_polling(qc);
 
-       case ATA_PROT_ATAPI:
-               ata_qc_set_polling(qc);
                ata_tf_to_host(ap, &qc->tf);
-               ata_port_queue_task(ap, atapi_packet_task, qc, 0);
+
+               if (qc->tf.flags & ATA_TFLAG_WRITE) {
+                       /* PIO data out protocol */
+                       ap->hsm_task_state = HSM_ST_FIRST;
+                       ata_port_queue_task(ap, ata_pio_task, ap, 0);
+
+                       /* always send first data block using
+                        * the ata_pio_task() codepath.
+                        */
+               } else {
+                       /* PIO data in protocol */
+                       ap->hsm_task_state = HSM_ST;
+
+                       if (qc->tf.flags & ATA_TFLAG_POLLING)
+                               ata_port_queue_task(ap, ata_pio_task, ap, 0);
+
+                       /* if polling, ata_pio_task() handles the rest.
+                        * otherwise, interrupt handler takes over from here.
+                        */
+               }
+
                break;
 
+       case ATA_PROT_ATAPI:
        case ATA_PROT_ATAPI_NODATA:
-               ap->flags |= ATA_FLAG_NOINTR;
+               if (qc->tf.flags & ATA_TFLAG_POLLING)
+                       ata_qc_set_polling(qc);
+
                ata_tf_to_host(ap, &qc->tf);
-               ata_port_queue_task(ap, atapi_packet_task, qc, 0);
+
+               ap->hsm_task_state = HSM_ST_FIRST;
+
+               /* send cdb by polling if no cdb interrupt */
+               if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
+                   (qc->tf.flags & ATA_TFLAG_POLLING))
+                       ata_port_queue_task(ap, ata_pio_task, ap, 0);
                break;
 
        case ATA_PROT_ATAPI_DMA:
-               ap->flags |= ATA_FLAG_NOINTR;
+               WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+
                ap->ops->tf_load(ap, &qc->tf);   /* load tf registers */
                ap->ops->bmdma_setup(qc);           /* set up bmdma */
-               ata_port_queue_task(ap, atapi_packet_task, qc, 0);
+               ap->hsm_task_state = HSM_ST_FIRST;
+
+               /* send cdb by polling if no cdb interrupt */
+               if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
+                       ata_port_queue_task(ap, ata_pio_task, ap, 0);
                break;
 
        default:
@@ -4266,52 +4442,66 @@ unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
 inline unsigned int ata_host_intr (struct ata_port *ap,
                                   struct ata_queued_cmd *qc)
 {
-       u8 status, host_stat;
-
-       switch (qc->tf.protocol) {
+       u8 status, host_stat = 0;
 
-       case ATA_PROT_DMA:
-       case ATA_PROT_ATAPI_DMA:
-       case ATA_PROT_ATAPI:
-               /* check status of DMA engine */
-               host_stat = ap->ops->bmdma_status(ap);
-               VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
-
-               /* if it's not our irq... */
-               if (!(host_stat & ATA_DMA_INTR))
-                       goto idle_irq;
-
-               /* before we do anything else, clear DMA-Start bit */
-               ap->ops->bmdma_stop(qc);
+       VPRINTK("ata%u: protocol %d task_state %d\n",
+               ap->id, qc->tf.protocol, ap->hsm_task_state);
 
-               /* fall through */
-
-       case ATA_PROT_ATAPI_NODATA:
-       case ATA_PROT_NODATA:
-               /* check altstatus */
-               status = ata_altstatus(ap);
-               if (status & ATA_BUSY)
-                       goto idle_irq;
+       /* Check whether we are expecting interrupt in this state */
+       switch (ap->hsm_task_state) {
+       case HSM_ST_FIRST:
+               /* Some pre-ATAPI-4 devices assert INTRQ
+                * at this state when ready to receive CDB.
+                */
 
-               /* check main status, clearing INTRQ */
-               status = ata_chk_status(ap);
-               if (unlikely(status & ATA_BUSY))
+               /* Check the ATA_DFLAG_CDB_INTR flag is enough here.
+                * The flag was turned on only for atapi devices.
+                * No need to check is_atapi_taskfile(&qc->tf) again.
+                */
+               if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
                        goto idle_irq;
-               DPRINTK("ata%u: protocol %d (dev_stat 0x%X)\n",
-                       ap->id, qc->tf.protocol, status);
-
-               /* ack bmdma irq events */
-               ap->ops->irq_clear(ap);
-
-               /* complete taskfile transaction */
-               qc->err_mask |= ac_err_mask(status);
-               ata_qc_complete(qc);
                break;
-
+       case HSM_ST_LAST:
+               if (qc->tf.protocol == ATA_PROT_DMA ||
+                   qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
+                       /* check status of DMA engine */
+                       host_stat = ap->ops->bmdma_status(ap);
+                       VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
+
+                       /* if it's not our irq... */
+                       if (!(host_stat & ATA_DMA_INTR))
+                               goto idle_irq;
+
+                       /* before we do anything else, clear DMA-Start bit */
+                       ap->ops->bmdma_stop(qc);
+
+                       if (unlikely(host_stat & ATA_DMA_ERR)) {
+                               /* error when transfering data to/from memory */
+                               qc->err_mask |= AC_ERR_HOST_BUS;
+                               ap->hsm_task_state = HSM_ST_ERR;
+                       }
+               }
+               break;
+       case HSM_ST:
+               break;
        default:
                goto idle_irq;
        }
 
+       /* check altstatus */
+       status = ata_altstatus(ap);
+       if (status & ATA_BUSY)
+               goto idle_irq;
+
+       /* check main status, clearing INTRQ */
+       status = ata_chk_status(ap);
+       if (unlikely(status & ATA_BUSY))
+               goto idle_irq;
+
+       /* ack bmdma irq events */
+       ap->ops->irq_clear(ap);
+
+       ata_hsm_move(ap, qc, status, 0);
        return 1;       /* irq handled */
 
 idle_irq:
@@ -4358,11 +4548,11 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
 
                ap = host_set->ports[i];
                if (ap &&
-                   !(ap->flags & (ATA_FLAG_DISABLED | ATA_FLAG_NOINTR))) {
+                   !(ap->flags & ATA_FLAG_DISABLED)) {
                        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.flags & ATA_TFLAG_POLLING)) &&
                            (qc->flags & ATA_QCFLAG_ACTIVE))
                                handled |= ata_host_intr(ap, qc);
                }