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, 6 deletions

diff --git a/drivers/ata/pata_at32.c b/drivers/ata/pata_at32.c
index db057b183d60..27c959f35c2c 100644
--- a/drivers/ata/pata_at32.c
+++ b/drivers/ata/pata_at32.c
@@ -166,11 +166,6 @@ static void pata_at32_set_piomode(struct ata_port *ap, struct ata_device *adev)
         }
 }
 
-static void pata_at32_irq_clear(struct ata_port *ap)
-{
-        /* No DMA controller yet */
-}
-
 static struct scsi_host_template at32_sht = {
         .module                 = THIS_MODULE,
         .name                   = DRV_NAME,
@@ -208,7 +203,7 @@ static struct ata_port_operations at32_port_ops = {
 
         .data_xfer              = ata_data_xfer,
 
-        .irq_clear              = pata_at32_irq_clear,
+        .irq_clear              = ata_noop_irq_clear,
         .irq_on                 = ata_irq_on,
 
         .port_start             = ata_sff_port_start,