libata: implement and use ata_noop_irq_clear()

->irq_clear() is used to clear IRQ bit of a SFF controller and isn't
useful for drivers which don't use libata SFF HSM implementation.
However, it's a required callback and many drivers implement their own
noop version as placeholder.  This patch implements ata_noop_irq_clear
and use it to replace those custom placeholders.

Also, SFF drivers which don't support BMDMA don't need to use
ata_bmdma_irq_clear().  It becomes noop if BMDMA address isn't
initialized.  Convert them to use ata_noop_irq_clear().

Signed-off-by: Tejun Heo <htejun@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/ata/pata_ixp4xx_cf.c b/drivers/ata/pata_ixp4xx_cf.c
index 030878fedeb5..83e38cc077e1 100644
--- a/drivers/ata/pata_ixp4xx_cf.c
+++ b/drivers/ata/pata_ixp4xx_cf.c
@@ -126,7 +126,7 @@ static struct ata_port_operations ixp4xx_port_ops = {
         .cable_detect           = ata_cable_40wire,
 
         .irq_handler            = ata_interrupt,
-        .irq_clear              = ata_bmdma_irq_clear,
+        .irq_clear              = ata_noop_irq_clear,
         .irq_on                 = ata_irq_on,
 
         .port_start             = ata_port_start,