[PATCH] libata: interrupt driven pio for LLD

libata.h:
libata-core:
  Add ATA_FLAG_PIO_POLLING flag for LLDs that expect interrupt for
command completion only.

sata_nv.c:
sata_vsc.c:
  irq handler is wrapper around ata_host_intr(), can handle PIO interrupts.

sata_promise.c:
sata_sx4.c:
sata_qstor.c:
sata_mv.c:
  Private irq handler.
  Polling mode ATA_FLAG_PIO_POLLING used for compatibility.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index cc2d1308826e..f8a590e59f10 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -3356,6 +3356,25 @@ 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)
+                                BUG();
+                        break;
+                default:
+                        break;
+                }
+        }
+
         /* select the device */
         ata_dev_select(ap, qc->dev->devno, 1, 0);