libata: Add helper to determine when PHY events should be ignored

This is a preparation commit that will allow to add other criteria
according to which PHY events should be dropped.

Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index f6cb1f1..12adcf7 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6752,6 +6752,25 @@
 	return tmp;
 }
 
+/**
+ *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
+ *	@link: Link receiving the event
+ *
+ *	Test whether the received PHY event has to be ignored or not.
+ *
+ *	LOCKING:
+ *	None:
+ *
+ *	RETURNS:
+ *	True if the event has to be ignored.
+ */
+bool sata_lpm_ignore_phy_events(struct ata_link *link)
+{
+	/* if LPM is enabled, PHYRDY doesn't mean anything */
+	return !!(link->lpm_policy > ATA_LPM_MAX_POWER);
+}
+EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
+
 /*
  * Dummy port_ops
  */