Fix bug - Implement bfin ata interrupt handler to avoid "irq 68 nobody cared" (v2)

Return IRQ_HANDLED when bfin ata device is busy.
http://blackfin.uclinux.org/gf/project/uclinux-dist/tracker/?action=TrackerItemEdit&tracker_item_id=3513

v1-v2:
 - fold api breakage fixing patch together.
 - mark 'static', not 'inline'.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 120 insertions, 4 deletions

diff --git a/drivers/ata/pata_bf54x.c b/drivers/ata/pata_bf54x.c
index a75de0684c15..9ab89732cf94 100644
--- a/drivers/ata/pata_bf54x.c
+++ b/drivers/ata/pata_bf54x.c
@@ -1272,8 +1272,8 @@ static void bfin_freeze(struct ata_port *ap)
 
 void bfin_thaw(struct ata_port *ap)
 {
+        dev_dbg(ap->dev, "in atapi dma thaw\n");
         bfin_check_status(ap);
-        bfin_irq_clear(ap);
         bfin_irq_on(ap);
 }
 
@@ -1339,13 +1339,130 @@ static int bfin_port_start(struct ata_port *ap)
         return 0;
 }
 
+static unsigned int bfin_ata_host_intr(struct ata_port *ap,
+                                   struct ata_queued_cmd *qc)
+{
+        struct ata_eh_info *ehi = &ap->link.eh_info;
+        u8 status, host_stat = 0;
+
+        VPRINTK("ata%u: protocol %d task_state %d\n",
+                ap->print_id, qc->tf.protocol, ap->hsm_task_state);
+
+        /* 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 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;
+                break;
+        case HSM_ST_LAST:
+                if (qc->tf.protocol == ATA_PROT_DMA ||
+                    qc->tf.protocol == ATAPI_PROT_DMA) {
+                        /* check status of DMA engine */
+                        host_stat = ap->ops->bmdma_status(ap);
+                        VPRINTK("ata%u: host_stat 0x%X\n",
+                                ap->print_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 = ap->ops->sff_check_altstatus(ap);
+        if (status & ATA_BUSY)
+                goto busy_ata;
+
+        /* check main status, clearing INTRQ */
+        status = ap->ops->sff_check_status(ap);
+        if (unlikely(status & ATA_BUSY))
+                goto busy_ata;
+
+        /* ack bmdma irq events */
+        ap->ops->sff_irq_clear(ap);
+
+        ata_sff_hsm_move(ap, qc, status, 0);
+
+        if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
+                                       qc->tf.protocol == ATAPI_PROT_DMA))
+                ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
+
+busy_ata:
+        return 1;       /* irq handled */
+
+idle_irq:
+        ap->stats.idle_irq++;
+
+#ifdef ATA_IRQ_TRAP
+        if ((ap->stats.idle_irq % 1000) == 0) {
+                ap->ops->irq_ack(ap, 0); /* debug trap */
+                ata_port_printk(ap, KERN_WARNING, "irq trap\n");
+                return 1;
+        }
+#endif
+        return 0;       /* irq not handled */
+}
+
+static irqreturn_t bfin_ata_interrupt(int irq, void *dev_instance)
+{
+        struct ata_host *host = dev_instance;
+        unsigned int i;
+        unsigned int handled = 0;
+        unsigned long flags;
+
+        /* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
+        spin_lock_irqsave(&host->lock, flags);
+
+        for (i = 0; i < host->n_ports; i++) {
+                struct ata_port *ap;
+
+                ap = host->ports[i];
+                if (ap &&
+                    !(ap->flags & ATA_FLAG_DISABLED)) {
+                        struct ata_queued_cmd *qc;
+
+                        qc = ata_qc_from_tag(ap, ap->link.active_tag);
+                        if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
+                            (qc->flags & ATA_QCFLAG_ACTIVE))
+                                handled |= bfin_ata_host_intr(ap, qc);
+                }
+        }
+
+        spin_unlock_irqrestore(&host->lock, flags);
+
+        return IRQ_RETVAL(handled);
+}
+
+
 static struct scsi_host_template bfin_sht = {
         ATA_BASE_SHT(DRV_NAME),
         .sg_tablesize           = SG_NONE,
         .dma_boundary           = ATA_DMA_BOUNDARY,
 };
 
-static const struct ata_port_operations bfin_pata_ops = {
+static struct ata_port_operations bfin_pata_ops = {
         .inherits               = &ata_sff_port_ops,
 
         .set_piomode            = bfin_set_piomode,
@@ -1370,7 +1487,6 @@ static const struct ata_port_operations bfin_pata_ops = {
         .thaw                   = bfin_thaw,
         .softreset              = bfin_softreset,
         .postreset              = bfin_postreset,
-        .post_internal_cmd      = bfin_bmdma_stop,
 
         .sff_irq_clear          = bfin_irq_clear,
         .sff_irq_on             = bfin_irq_on,
@@ -1507,7 +1623,7 @@ static int __devinit bfin_atapi_probe(struct platform_device *pdev)
         }
 
         if (ata_host_activate(host, platform_get_irq(pdev, 0),
-                ata_sff_interrupt, IRQF_SHARED, &bfin_sht) != 0) {
+                bfin_ata_interrupt, IRQF_SHARED, &bfin_sht) != 0) {
                 peripheral_free_list(atapi_io_port);
                 dev_err(&pdev->dev, "Fail to attach ATAPI device\n");
                 return -ENODEV;