libata: make sff_irq_on() method optional

Now, with the introduction of the sff_set_devctl() method, we can
use it in sff_irq_on() method too -- that way its implementations
in 'pata_bf54x' and 'pata_scc' become virtually identical to
ata_sff_irq_on().  The sff_irq_on() method now becomes quite
superfluous, and the only reason not to remove it completely is
the existence of the 'pata_octeon_cf' driver which implements it
as an empty function. Just make the method optional then, with
ata_sff_irq_on() becoming generic taskfile-bound function, still
global for the 'pata_bf54x' driver to be able to call it from its
thaw() and postreset() methods.

While at it, make the sff_irq_on() method and ata_sff_irq_on() return
'void' as the result is always ignored anyway.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/libata-sff.c

@@ -63,7 +63,6 @@ const struct ata_port_operations ata_sff_port_ops = {
 	.sff_tf_read		= ata_sff_tf_read,
 	.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,
 
 	.lost_interrupt		= ata_sff_lost_interrupt,
@@ -538,24 +537,29 @@ void ata_dev_select(struct ata_port *ap, unsigned int device,
  *	Enable interrupts on a legacy IDE device using MMIO or PIO,
  *	wait for idle, clear any pending interrupts.
  *
+ *	Note: may NOT be used as the sff_irq_on() entry in
+ *	ata_port_operations.
+ *
  *	LOCKING:
  *	Inherited from caller.
  */
-u8 ata_sff_irq_on(struct ata_port *ap)
+void ata_sff_irq_on(struct ata_port *ap)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
-	u8 tmp;
+
+	if (ap->ops->sff_irq_on) {
+		ap->ops->sff_irq_on(ap);
+		return;
+	}
 
 	ap->ctl &= ~ATA_NIEN;
 	ap->last_ctl = ap->ctl;
 
-	if (ioaddr->ctl_addr)
-		iowrite8(ap->ctl, ioaddr->ctl_addr);
-	tmp = ata_wait_idle(ap);
+	if (ap->ops->sff_set_devctl || ioaddr->ctl_addr)
+		ata_sff_set_devctl(ap, ap->ctl);
+	ata_wait_idle(ap);
 
 	ap->ops->sff_irq_clear(ap);
-
-	return tmp;
 }
 EXPORT_SYMBOL_GPL(ata_sff_irq_on);
 
@@ -1186,7 +1190,7 @@ static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
 			qc = ata_qc_from_tag(ap, qc->tag);
 			if (qc) {
 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
-					ap->ops->sff_irq_on(ap);
+					ata_sff_irq_on(ap);
 					ata_qc_complete(qc);
 				} else
 					ata_port_freeze(ap);
@@ -1202,7 +1206,7 @@ static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
 	} else {
 		if (in_wq) {
 			spin_lock_irqsave(ap->lock, flags);
-			ap->ops->sff_irq_on(ap);
+			ata_sff_irq_on(ap);
 			ata_qc_complete(qc);
 			spin_unlock_irqrestore(ap->lock, flags);
 		} else
@@ -1946,7 +1950,7 @@ void ata_sff_thaw(struct ata_port *ap)
 	/* clear & re-enable interrupts */
 	ap->ops->sff_check_status(ap);
 	ap->ops->sff_irq_clear(ap);
-	ap->ops->sff_irq_on(ap);
+	ata_sff_irq_on(ap);
 }
 EXPORT_SYMBOL_GPL(ata_sff_thaw);
 

drivers/ata/pata_bf54x.c

@@ -1227,30 +1227,6 @@ static void bfin_irq_clear(struct ata_port *ap)
 		| MULTI_TERM_INT | UDMAIN_TERM_INT | UDMAOUT_TERM_INT);
 }
 
-/**
- *	bfin_irq_on - Enable interrupts on a port.
- *	@ap: Port on which interrupts are enabled.
- *
- *	Note: Original code is ata_sff_irq_on().
- */
-
-static unsigned char bfin_irq_on(struct ata_port *ap)
-{
-	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
-	u8 tmp;
-
-	dev_dbg(ap->dev, "in atapi irq on\n");
-	ap->ctl &= ~ATA_NIEN;
-	ap->last_ctl = ap->ctl;
-
-	write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
-	tmp = ata_wait_idle(ap);
-
-	bfin_irq_clear(ap);
-
-	return tmp;
-}
-
 /**
  *	bfin_thaw - Thaw DMA controller port
  *	@ap: port to thaw
@@ -1262,7 +1238,7 @@ void bfin_thaw(struct ata_port *ap)
 {
 	dev_dbg(ap->dev, "in atapi dma thaw\n");
 	bfin_check_status(ap);
-	bfin_irq_on(ap);
+	ata_sff_irq_on(ap);
 }
 
 /**
@@ -1279,7 +1255,7 @@ static void bfin_postreset(struct ata_link *link, unsigned int *classes)
 	void __iomem *base = (void __iomem *)ap->ioaddr.ctl_addr;
 
 	/* re-enable interrupts */
-	bfin_irq_on(ap);
+	ata_sff_irq_on(ap);
 
 	/* is double-select really necessary? */
 	if (classes[0] != ATA_DEV_NONE)
@@ -1477,7 +1453,6 @@ static struct ata_port_operations bfin_pata_ops = {
 	.postreset		= bfin_postreset,
 
 	.sff_irq_clear		= bfin_irq_clear,
-	.sff_irq_on		= bfin_irq_on,
 
 	.port_start		= bfin_port_start,
 	.port_stop		= bfin_port_stop,

drivers/ata/pata_octeon_cf.c

@@ -489,9 +489,8 @@ static void octeon_cf_exec_command16(struct ata_port *ap,
 	ata_wait_idle(ap);
 }
 
-static u8 octeon_cf_irq_on(struct ata_port *ap)
+static void octeon_cf_irq_on(struct ata_port *ap)
 {
-	return 0;
 }
 
 static void octeon_cf_irq_clear(struct ata_port *ap)

drivers/ata/pata_scc.c

@@ -827,29 +827,6 @@ static unsigned int scc_data_xfer (struct ata_device *dev, unsigned char *buf,
 	return words << 1;
 }
 
-/**
- *	scc_irq_on - Enable interrupts on a port.
- *	@ap: Port on which interrupts are enabled.
- *
- *	Note: Original code is ata_sff_irq_on().
- */
-
-static u8 scc_irq_on (struct ata_port *ap)
-{
-	struct ata_ioports *ioaddr = &ap->ioaddr;
-	u8 tmp;
-
-	ap->ctl &= ~ATA_NIEN;
-	ap->last_ctl = ap->ctl;
-
-	out_be32(ioaddr->ctl_addr, ap->ctl);
-	tmp = ata_wait_idle(ap);
-
-	ap->ops->sff_irq_clear(ap);
-
-	return tmp;
-}
-
 /**
  *	scc_pata_prereset - prepare for reset
  *	@ap: ATA port to be reset
@@ -977,7 +954,6 @@ static struct ata_port_operations scc_pata_ops = {
 	.post_internal_cmd	= scc_bmdma_stop,
 
 	.sff_irq_clear		= scc_irq_clear,
-	.sff_irq_on		= scc_irq_on,
 
 	.port_start		= scc_port_start,
 	.port_stop		= scc_port_stop,

include/linux/libata.h

@@ -859,7 +859,7 @@ struct ata_port_operations {
 				 const struct ata_taskfile *tf);
 	unsigned int (*sff_data_xfer)(struct ata_device *dev,
 			unsigned char *buf, unsigned int buflen, int rw);
-	u8   (*sff_irq_on)(struct ata_port *);
+	void (*sff_irq_on)(struct ata_port *);
 	bool (*sff_irq_check)(struct ata_port *);
 	void (*sff_irq_clear)(struct ata_port *);
 
@@ -1599,7 +1599,7 @@ extern unsigned int ata_sff_data_xfer32(struct ata_device *dev,
 			unsigned char *buf, unsigned int buflen, int rw);
 extern unsigned int ata_sff_data_xfer_noirq(struct ata_device *dev,
 			unsigned char *buf, unsigned int buflen, int rw);
-extern u8 ata_sff_irq_on(struct ata_port *ap);
+extern void ata_sff_irq_on(struct ata_port *ap);
 extern void ata_sff_irq_clear(struct ata_port *ap);
 extern int ata_sff_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
 			    u8 status, int in_wq);