Improve irq handler such that it considers irq_stat if available.
Note that this patch introduces the following two behavior changes.
* if irq_stat is available and device interrupt is not reported,
BMDMA/TF registers are never quiried.
* if irq_stat is available and device interrupt is reported, irq
handler will return IRQ_HANDLED regardless of BMDMA/TF status.
This change also makes later hotplug change easier to integrate.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/sata_nv.c | 55 +++++++++++++++++++++++++++++++++++-------------
1 files changed, 40 insertions(+), 15 deletions(-)
77fddbda2987defb2491ba370746daa380bb5c11
diff --git a/drivers/scsi/sata_nv.c b/drivers/scsi/sata_nv.c
index 93e74aa..f1218e5 100644
--- a/drivers/scsi/sata_nv.c
+++ b/drivers/scsi/sata_nv.c
@@ -291,33 +291,58 @@ static void ck804_clr_irq_status(struct
writeb(0xff, host_set->mmio_base + NV_INT_STATUS_CK804);
}
+static int nv_host_intr(struct ata_port *ap, int irq_stat_valid, u8 irq_stat)
+{
+ struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->active_tag);
+ int handled;
+
+ /* bail out if not our interrupt */
+ if (irq_stat_valid && !(irq_stat & NV_INT_DEV))
+ return 0;
+
+ /* No request pending? Clear interrupt status anyway, in case
+ * there's one pending.
+ */
+ if (unlikely(!qc || (qc->tf.flags & ATA_TFLAG_POLLING))) {
+ ata_check_status(ap);
+ return irq_stat_valid;
+ }
+
+ handled = ata_host_intr(ap, qc);
+ if (unlikely(!handled) && irq_stat_valid) {
+ /* spurious interrupt, clear it */
+ ata_check_status(ap);
+ handled++;
+ }
+
+ return handled;
+}
+
static irqreturn_t nv_interrupt (int irq, void *dev_instance,
struct pt_regs *regs)
{
struct ata_host_set *host_set = dev_instance;
+ struct nv_host_desc *host_desc = host_set->private_data;
+ int irq_stat_valid = 0;
+ u8 irq_stat = 0;
unsigned int i;
unsigned int handled = 0;
unsigned long flags;
spin_lock_irqsave(&host_set->lock, flags);
+ if (host_desc->get_irq_status) {
+ irq_stat_valid = 1;
+ irq_stat = host_desc->get_irq_status(host_set);
+ }
+
for (i = 0; i < host_set->n_ports; i++) {
- struct ata_port *ap;
-
- ap = host_set->ports[i];
- if (ap &&
- !(ap->flags & ATA_FLAG_DISABLED)) {
- struct ata_queued_cmd *qc;
-
- qc = ata_qc_from_tag(ap, ap->active_tag);
- if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)))
- handled += ata_host_intr(ap, qc);
- else
- // No request pending? Clear interrupt status
- // anyway, in case there's one pending.
- ap->ops->check_status(ap);
- }
+ struct ata_port *ap = host_set->ports[i];
+
+ if (ap && !(ap->flags & ATA_FLAG_DISABLED))
+ handled += nv_host_intr(ap, irq_stat_valid, irq_stat);
+ irq_stat >>= NV_INT_PORT_SHIFT;
}
spin_unlock_irqrestore(&host_set->lock, flags);
--
1.3.2
-
: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
