sata_mv: async notify for genIIe only

Now that we handle the FIS_IRQ_CAUSE register correctly,
we can also now handle SATA asynchronous notification events.

So enable them, but only for the more modern GenIIe chips.
(older chips have unaddressed errata issues related to this).

This fixes hot plug/unplug for port-muliplier ports.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/sata_mv.c

@@ -133,7 +133,7 @@ enum {
 
 	MV_GENIIE_FLAGS		= MV_COMMON_FLAGS | MV_6XXX_FLAGS |
 				  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
-				  ATA_FLAG_NCQ,
+				  ATA_FLAG_NCQ | ATA_FLAG_AN,
 
 	CRQB_FLAG_READ		= (1 << 0),
 	CRQB_TAG_SHIFT		= 1,
@@ -226,6 +226,7 @@ enum {
 	SATA_STATUS_OFS		= 0x300,  /* ctrl, err regs follow status */
 	SATA_ACTIVE_OFS		= 0x350,
 	SATA_FIS_IRQ_CAUSE_OFS	= 0x364,
+	SATA_FIS_IRQ_AN		= (1 << 9),	/* async notification */
 
 	LTMODE_OFS		= 0x30c,
 	LTMODE_BIT8		= (1 << 8),	/* unknown, but necessary */
@@ -1849,8 +1850,17 @@ static void mv_err_intr(struct ata_port *ap)
 	ata_ehi_push_desc(ehi, "edma_err_cause=%08x pp_flags=%08x",
 			  edma_err_cause, pp->pp_flags);
 
-	if (IS_GEN_IIE(hpriv) && (edma_err_cause & EDMA_ERR_TRANS_IRQ_7))
+	if (IS_GEN_IIE(hpriv) && (edma_err_cause & EDMA_ERR_TRANS_IRQ_7)) {
 		ata_ehi_push_desc(ehi, "fis_cause=%08x", fis_cause);
+		if (fis_cause & SATA_FIS_IRQ_AN) {
+			u32 ec = edma_err_cause &
+			       ~(EDMA_ERR_TRANS_IRQ_7 | EDMA_ERR_IRQ_TRANSIENT);
+			sata_async_notification(ap);
+			if (!ec)
+				return; /* Just an AN; no need for the nukes */
+			ata_ehi_push_desc(ehi, "SDB notify");
+		}
+	}
 	/*
 	 * All generations share these EDMA error cause bits:
 	 */