libata: clean up port_ops->sff_irq_clear()

->sff_irq_clear() is called only from SFF interrupt handler, so there
is no reason to initialize it for non-SFF controllers.  Also,
ata_sff_irq_clear() can handle both BMDMA and non-BMDMA SFF
controllers.

This patch kills ata_noop_irq_clear() and removes it from base
port_ops and sets ->sff_irq_clear to ata_sff_irq_clear() in sff
port_ops instead of bmdma port_ops.
Signed-off-by: Tejun Heo <htejun@gmail.com>

drivers/ata/libata-core.c

@@ -74,7 +74,6 @@ const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
 
 const struct ata_port_operations ata_base_port_ops = {
-	.sff_irq_clear		= ata_noop_irq_clear,
 	.prereset		= ata_sff_prereset,
 	.hardreset		= sata_sff_hardreset,
 	.postreset		= ata_sff_postreset,
@@ -386,14 +385,6 @@ int atapi_cmd_type(u8 opcode)
 	}
 }
 
-/**
- *	ata_noop_irq_clear - Noop placeholder for irq_clear
- *	@ap: Port associated with this ATA transaction.
- */
-void ata_noop_irq_clear(struct ata_port *ap)
-{
-}
-
 /**
  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
  *	@tf: Taskfile to convert
@@ -6108,7 +6099,6 @@ EXPORT_SYMBOL_GPL(ata_port_start);
 EXPORT_SYMBOL_GPL(ata_do_set_mode);
 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
-EXPORT_SYMBOL_GPL(ata_noop_irq_clear);
 EXPORT_SYMBOL_GPL(ata_port_probe);
 EXPORT_SYMBOL_GPL(ata_dev_disable);
 EXPORT_SYMBOL_GPL(sata_set_spd);

drivers/ata/libata-sff.c

@@ -58,6 +58,7 @@ const struct ata_port_operations ata_sff_port_ops = {
 	.sff_exec_command	= ata_sff_exec_command,
 	.sff_data_xfer		= ata_sff_data_xfer,
 	.sff_irq_on		= ata_sff_irq_on,
+	.sff_irq_clear		= ata_sff_irq_clear,
 
 	.port_start		= ata_sff_port_start,
 };
@@ -71,7 +72,6 @@ const struct ata_port_operations ata_bmdma_port_ops = {
 	.bmdma_start		= ata_bmdma_start,
 	.bmdma_stop		= ata_bmdma_stop,
 	.bmdma_status		= ata_bmdma_status,
-	.sff_irq_clear		= ata_sff_irq_clear,
 };
 
 /**

include/linux/libata.h

@@ -896,7 +896,6 @@ extern void ata_id_string(const u16 *id, unsigned char *s,
 			  unsigned int ofs, unsigned int len);
 extern void ata_id_c_string(const u16 *id, unsigned char *s,
 			    unsigned int ofs, unsigned int len);
-extern void ata_noop_irq_clear(struct ata_port *ap);
 extern void ata_qc_complete(struct ata_queued_cmd *qc);
 extern int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
 				    void (*finish_qc)(struct ata_queued_cmd *));