[libata] create, and use, ->irq_clear hook

This is more conservative in general, and so applies to multiple
controllers.  Specifically it attempts to address irq-related issues
on the Intel ICH5/6 hardware.  On Intel ICH5/6, the BMDMA 'interrupt'
status bit will be set even on non-DMA commands, which software
(and I) did not expect.

This change clears pending interrupts once upon initialization,
and then each time ata_irq_on() is called.

drivers/scsi/ata_piix.c

@@ -143,6 +143,7 @@ static struct ata_port_operations piix_pata_ops = {
 	.eng_timeout		= ata_eng_timeout,
 
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 
 	.port_start		= ata_port_start,
 	.port_stop		= ata_port_stop,
@@ -168,6 +169,7 @@ static struct ata_port_operations piix_sata_ops = {
 	.eng_timeout		= ata_eng_timeout,
 
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 
 	.port_start		= ata_port_start,
 	.port_stop		= ata_port_stop,

drivers/scsi/libata-core.c

@@ -2537,6 +2537,11 @@ void ata_bmdma_start_pio (struct ata_queued_cmd *qc)
 	     ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
 }
 
+void ata_bmdma_irq_clear(struct ata_port *ap)
+{
+	ata_bmdma_ack_irq(ap);
+}
+
 /**
  *	ata_host_intr - Handle host interrupt for given (port, task)
  *	@ap: Port on which interrupt arrived (possibly...)
@@ -2879,6 +2884,7 @@ int ata_device_add(struct ata_probe_ent *ent)
 	host_set->irq = ent->irq;
 	host_set->mmio_base = ent->mmio_base;
 	host_set->private_data = ent->private_data;
+	host_set->ops = ent->port_ops;
 
 	/* register each port bound to this device */
 	for (i = 0; i < ent->n_ports; i++) {
@@ -2901,6 +2907,8 @@ int ata_device_add(struct ata_probe_ent *ent)
 	       		ap->ioaddr.bmdma_addr,
 	       		ent->irq);
 
+		ata_chk_status(ap);
+		host_set->ops->irq_clear(ap);
 		count++;
 	}
 
@@ -2909,10 +2917,6 @@ int ata_device_add(struct ata_probe_ent *ent)
 		return 0;
 	}
 
-	/* TODO: ack irq here, to ensure it won't scream
-	 * when we enable it?
-	 */
-
 	/* obtain irq, that is shared between channels */
 	if (request_irq(ent->irq, ent->port_ops->irq_handler, ent->irq_flags,
 			DRV_NAME, host_set))
@@ -3238,8 +3242,8 @@ void ata_pci_remove_one (struct pci_dev *pdev)
 	free_irq(host_set->irq, host_set);
 	if (host_set->mmio_base)
 		iounmap(host_set->mmio_base);
-	if (host_set->ports[0]->ops->host_stop)
-		host_set->ports[0]->ops->host_stop(host_set);
+	if (host_set->ops->host_stop)
+		host_set->ops->host_stop(host_set);
 
 	for (i = 0; i < host_set->n_ports; i++) {
 		ap = host_set->ports[i];
@@ -3363,6 +3367,7 @@ EXPORT_SYMBOL_GPL(ata_bmdma_setup_pio);
 EXPORT_SYMBOL_GPL(ata_bmdma_start_pio);
 EXPORT_SYMBOL_GPL(ata_bmdma_setup_mmio);
 EXPORT_SYMBOL_GPL(ata_bmdma_start_mmio);
+EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
 EXPORT_SYMBOL_GPL(ata_port_probe);
 EXPORT_SYMBOL_GPL(sata_phy_reset);
 EXPORT_SYMBOL_GPL(ata_bus_reset);

drivers/scsi/sata_nv.c

@@ -142,6 +142,7 @@ static struct ata_port_operations nv_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= nv_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 	.scr_read		= nv_scr_read,
 	.scr_write		= nv_scr_write,
 	.port_start		= ata_port_start,

drivers/scsi/sata_promise.c

@@ -86,6 +86,7 @@ static void pdc_tf_load_mmio(struct ata_port *ap, struct ata_taskfile *tf);
 static void pdc_exec_command_mmio(struct ata_port *ap, struct ata_taskfile *tf);
 static inline void pdc_dma_complete (struct ata_port *ap,
                                      struct ata_queued_cmd *qc, int have_err);
+static void pdc_irq_clear(struct ata_port *ap);
 
 static Scsi_Host_Template pdc_sata_sht = {
 	.module			= THIS_MODULE,
@@ -118,6 +119,7 @@ static struct ata_port_operations pdc_sata_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= pdc_eng_timeout,
 	.irq_handler		= pdc_interrupt,
+	.irq_clear		= pdc_irq_clear,
 	.scr_read		= pdc_sata_scr_read,
 	.scr_write		= pdc_sata_scr_write,
 	.port_start		= pdc_port_start,
@@ -379,6 +381,14 @@ static inline unsigned int pdc_host_intr( struct ata_port *ap,
         return handled;
 }
 
+static void pdc_irq_clear(struct ata_port *ap)
+{
+	struct ata_host_set *host_set = ap->host_set;
+	void *mmio = host_set->mmio_base;
+
+	readl(mmio + PDC_INT_SEQMASK);
+}
+
 static irqreturn_t pdc_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
 {
 	struct ata_host_set *host_set = dev_instance;

drivers/scsi/sata_sil.c

@@ -136,6 +136,7 @@ static struct ata_port_operations sil_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 	.scr_read		= sil_scr_read,
 	.scr_write		= sil_scr_write,
 	.port_start		= ata_port_start,

drivers/scsi/sata_sis.c

@@ -104,6 +104,7 @@ static struct ata_port_operations sis_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 	.scr_read		= sis_scr_read,
 	.scr_write		= sis_scr_write,
 	.port_start		= ata_port_start,

drivers/scsi/sata_svw.c

@@ -237,6 +237,7 @@ static struct ata_port_operations k2_sata_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 	.scr_read		= k2_sata_scr_read,
 	.scr_write		= k2_sata_scr_write,
 	.port_start		= ata_port_start,

drivers/scsi/sata_sx4.c

@@ -171,6 +171,7 @@ static void pdc20621_get_from_dimm(struct ata_probe_ent *pe,
 #endif
 static void pdc20621_put_to_dimm(struct ata_probe_ent *pe, 
 				 void *psource, u32 offset, u32 size);
+static void pdc20621_irq_clear(struct ata_port *ap);
 
 
 static Scsi_Host_Template pdc_sata_sht = {
@@ -204,6 +205,7 @@ static struct ata_port_operations pdc_20621_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= pdc_eng_timeout,
 	.irq_handler		= pdc20621_interrupt,
+	.irq_clear		= pdc20621_irq_clear,
 	.port_start		= pdc_port_start,
 	.port_stop		= pdc_port_stop,
 	.host_stop		= pdc20621_host_stop,
@@ -703,6 +705,16 @@ static inline unsigned int pdc20621_host_intr( struct ata_port *ap,
 	return handled;
 }
 
+static void pdc20621_irq_clear(struct ata_port *ap)
+{
+	struct ata_host_set *host_set = ap->host_set;
+	void *mmio = host_set->mmio_base;
+
+	mmio += PDC_CHIP0_OFS;
+
+	readl(mmio + PDC_20621_SEQMASK);
+}
+
 static irqreturn_t pdc20621_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
 {
 	struct ata_host_set *host_set = dev_instance;

drivers/scsi/sata_via.c

@@ -114,6 +114,7 @@ static struct ata_port_operations svia_sata_ops = {
 	.eng_timeout		= ata_eng_timeout,
 
 	.irq_handler		= ata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 
 	.scr_read		= svia_scr_read,
 	.scr_write		= svia_scr_write,

drivers/scsi/sata_vsc.c

@@ -219,6 +219,7 @@ static struct ata_port_operations vsc_sata_ops = {
 	.qc_issue		= ata_qc_issue_prot,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= vsc_sata_interrupt,
+	.irq_clear		= ata_bmdma_irq_clear,
 	.scr_read		= vsc_sata_scr_read,
 	.scr_write		= vsc_sata_scr_write,
 	.port_start		= ata_port_start,

include/linux/libata.h

@@ -202,6 +202,7 @@ struct ata_host_set {
 	void			*mmio_base;
 	unsigned int		n_ports;
 	void			*private_data;
+	struct ata_port_operations *ops;
 	struct ata_port *	ports[0];
 };
 
@@ -318,6 +319,7 @@ struct ata_port_operations {
 	void (*eng_timeout) (struct ata_port *ap);
 
 	irqreturn_t (*irq_handler)(int, void *, struct pt_regs *);
+	void (*irq_clear) (struct ata_port *);
 
 	u32 (*scr_read) (struct ata_port *ap, unsigned int sc_reg);
 	void (*scr_write) (struct ata_port *ap, unsigned int sc_reg,
@@ -382,6 +384,7 @@ extern void ata_bmdma_setup_mmio (struct ata_queued_cmd *qc);
 extern void ata_bmdma_start_mmio (struct ata_queued_cmd *qc);
 extern void ata_bmdma_setup_pio (struct ata_queued_cmd *qc);
 extern void ata_bmdma_start_pio (struct ata_queued_cmd *qc);
+extern void ata_bmdma_irq_clear(struct ata_port *ap);
 extern int pci_test_config_bits(struct pci_dev *pdev, struct pci_bits *bits);
 extern void ata_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat);
 extern void ata_eng_timeout(struct ata_port *ap);
@@ -484,6 +487,7 @@ static inline void ata_tf_init(struct ata_port *ap, struct ata_taskfile *tf, uns
 static inline u8 ata_irq_on(struct ata_port *ap)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
+	u8 tmp;
 
 	ap->ctl &= ~ATA_NIEN;
 	ap->last_ctl = ap->ctl;
@@ -492,7 +496,11 @@ static inline u8 ata_irq_on(struct ata_port *ap)
 		writeb(ap->ctl, ioaddr->ctl_addr);
 	else
 		outb(ap->ctl, ioaddr->ctl_addr);
-	return ata_wait_idle(ap);
+	tmp = ata_wait_idle(ap);
+
+	ap->ops->irq_clear(ap);
+
+	return tmp;
 }
 
 static inline u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq)