[libata] Remove ->irq_ack() hook, and ata_dummy_irq_on()

* ->irq_ack() is redundant to what the irq handler already
  performs... chk-status + irq-clear.  Furthermore, it is only
  called in one place, when screaming-irq-debugging is enabled,
  so we don't want to bother with a hook just for that.

* ata_dummy_irq_on() is only ever used in drivers that have
  no callpath reaching ->irq_on().  Remove .irq_on hook from
  those drivers, and the now-unused ata_dummy_irq_on()

Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 0 insertions, 1 deletions

diff --git a/drivers/ata/pata_sc1200.c b/drivers/ata/pata_sc1200.c
index 5edf67b1f3bf..61edff4a5c6e 100644
--- a/drivers/ata/pata_sc1200.c
+++ b/drivers/ata/pata_sc1200.c
@@ -227,7 +227,6 @@ static struct ata_port_operations sc1200_port_ops = {
         .irq_handler    = ata_interrupt,
         .irq_clear      = ata_bmdma_irq_clear,
         .irq_on         = ata_irq_on,
-        .irq_ack        = ata_irq_ack,
 
         .port_start     = ata_port_start,
 };