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_isapnp.c b/drivers/ata/pata_isapnp.c
index 4320e7986321..ef561de0c24d 100644
--- a/drivers/ata/pata_isapnp.c
+++ b/drivers/ata/pata_isapnp.c
@@ -55,7 +55,7 @@ static struct ata_port_operations isapnp_port_ops = {
 
         .data_xfer      = ata_data_xfer,
 
-        .irq_clear      = ata_bmdma_irq_clear,
+        .irq_clear      = ata_noop_irq_clear,
         .irq_on         = ata_irq_on,
 
         .port_start     = ata_sff_port_start,