1 files changed, 22 insertions, 11 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 9a6aacf467b..c92439fe5da 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -3350,11 +3350,13 @@ int ata_qc_issue_prot(struct ata_queued_cmd *qc)
                 break;
 
         case ATA_PROT_ATAPI_NODATA:
+                ap->flags |= ATA_FLAG_NOINTR;
                 ata_tf_to_host_nolock(ap, &qc->tf);
                 queue_work(ata_wq, &ap->packet_task);
                 break;
 
         case ATA_PROT_ATAPI_DMA:
+                ap->flags |= ATA_FLAG_NOINTR;
                 ap->ops->tf_load(ap, &qc->tf);   /* load tf registers */
                 ap->ops->bmdma_setup(qc);           /* set up bmdma */
                 queue_work(ata_wq, &ap->packet_task);
@@ -3708,7 +3710,8 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
                 struct ata_port *ap;
 
                 ap = host_set->ports[i];
-                if (ap && (!(ap->flags & ATA_FLAG_PORT_DISABLED))) {
+                if (ap &&
+                    !(ap->flags & (ATA_FLAG_PORT_DISABLED | ATA_FLAG_NOINTR))) {
                         struct ata_queued_cmd *qc;
 
                         qc = ata_qc_from_tag(ap, ap->active_tag);
@@ -3760,19 +3763,27 @@ static void atapi_packet_task(void *_data)
         /* send SCSI cdb */
         DPRINTK("send cdb\n");
         assert(ap->cdb_len >= 12);
-        ata_data_xfer(ap, qc->cdb, ap->cdb_len, 1);
 
-        /* if we are DMA'ing, irq handler takes over from here */
-        if (qc->tf.protocol == ATA_PROT_ATAPI_DMA)
-                ap->ops->bmdma_start(qc);           /* initiate bmdma */
+        if (qc->tf.protocol == ATA_PROT_ATAPI_DMA ||
+            qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
+                unsigned long flags;
 
-        /* non-data commands are also handled via irq */
-        else if (qc->tf.protocol == ATA_PROT_ATAPI_NODATA) {
-                /* do nothing */
-        }
+                /* 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, ap->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, ap->cdb_len, 1);
 
-        /* PIO commands are handled by polling */
-        else {
+                /* PIO commands are handled by polling */
                 ap->pio_task_state = PIO_ST;
                 queue_work(ata_wq, &ap->pio_task);
         }