[PATCH v3 1/1] net: phylink: add phylink_set_mac_pm() helper

[Shenwei Wang <shenwei.wang@nxp.com>]

The recent commit

'commit 47ac7b2f6a1f ("net: phy: Warn about incorrect
mdio_bus_phy_resume() state")'

requires the MAC driver explicitly tell the phy driver who is
managing the PM, otherwise you will see warning during resume
stage.

Add a helper to let the MAC driver has a way to tell the PHY
driver it will manage the PM.

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
---
 Changes in v3:
  - update the API description according to Russell's feedback.

 Changes in v2:
  - add the API description
  - remove the unneccesary ASSERT_RTNL();

 drivers/net/phy/phylink.c | 18 ++++++++++++++++++
 include/linux/phylink.h   |  1 +
 2 files changed, 19 insertions(+)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index e9d62f9598f9..e78d9aef7a7c 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1722,6 +1722,24 @@ void phylink_stop(struct phylink *pl)
 }
 EXPORT_SYMBOL_GPL(phylink_stop);

+/**
+ * phylink_set_mac_pm() - set phydev->mac_managed_pm to true
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ *
+ * Set the phydev->mac_managed_pm, which is under the phylink instance
+ * specified by @pl, to true. This is to indicate that the MAC driver is
+ * responsible for PHY PM.
+ *
+ * The function can be called in the end of net_device_ops ndo_open() method
+ * or any place after phy is connected.
+ */
+void phylink_set_mac_pm(struct phylink *pl)
+{
+	if (pl->phydev)
+		pl->phydev->mac_managed_pm = true;
+}
+EXPORT_SYMBOL_GPL(phylink_set_mac_pm);
+
 /**
  * phylink_suspend() - handle a network device suspend event
  * @pl: a pointer to a &struct phylink returned from phylink_create()
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 6d06896fc20d..cfcc680462b9 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -540,6 +540,7 @@ void phylink_mac_change(struct phylink *, bool up);

 void phylink_start(struct phylink *);
 void phylink_stop(struct phylink *);
+void phylink_set_mac_pm(struct phylink *pl);

 void phylink_suspend(struct phylink *pl, bool mac_wol);
 void phylink_resume(struct phylink *pl);
--
2.34.1