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, 5 deletions

diff --git a/drivers/ata/pata_rb500_cf.c b/drivers/ata/pata_rb500_cf.c
index 4ce9b03fe6c8..08c32af1c84d 100644
--- a/drivers/ata/pata_rb500_cf.c
+++ b/drivers/ata/pata_rb500_cf.c
@@ -117,10 +117,6 @@ static irqreturn_t rb500_pata_irq_handler(int irq, void *dev_instance)
         return IRQ_HANDLED;
 }
 
-static void rb500_pata_irq_clear(struct ata_port *ap)
-{
-}
-
 static int rb500_pata_port_start(struct ata_port *ap)
 {
         return 0;
@@ -144,7 +140,7 @@ static struct ata_port_operations rb500_pata_port_ops = {
         .error_handler          = ata_bmdma_error_handler,
 
         .irq_handler            = rb500_pata_irq_handler,
-        .irq_clear              = rb500_pata_irq_clear,
+        .irq_clear              = ata_noop_irq_clear,
         .irq_on                 = ata_irq_on,
 
         .port_start             = rb500_pata_port_start,