net: phylink: add phylink_prepare_resume()

Add a resume preparation function, which will ensure that the receive
clock from the PHY is appropriately configured while resuming.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

2 files changed, 25 insertions, 0 deletions

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 10687f50c95c..91506ed192e8 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -2657,6 +2657,30 @@ void phylink_suspend(struct phylink *pl, bool mac_wol)
 EXPORT_SYMBOL_GPL(phylink_suspend);
 
 /**
+ * phylink_prepare_resume() - prepare to resume a network device
+ * @pl: a pointer to a &struct phylink returned from phylink_create()
+ *
+ * Optional, thus must be called prior to phylink_resume().
+ *
+ * Prepare to resume a network device, preparing the PHY as necessary.
+ */
+void phylink_prepare_resume(struct phylink *pl)
+{
+	ASSERT_RTNL();
+
+	/* If the MAC requires the receive clock, but receive clock
+	 * stop was enabled at the PHY, we need to ensure that the
+	 * receive clock is running. Disable receive clock stop.
+	 * phylink_resume() will re-enable it if necessary.
+	 */
+	if (pl->mac_supports_eee_ops && pl->phydev &&
+	    pl->config->mac_requires_rxc &&
+	    pl->config->eee_rx_clk_stop_enable)
+		phy_eee_rx_clock_stop(pl->phydev, false);
+}
+EXPORT_SYMBOL_GPL(phylink_prepare_resume);
+
+/**
  * phylink_resume() - handle a network device resume 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 41ab85e591ad..e7059ad47e20 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -701,6 +701,7 @@ void phylink_start(struct phylink *);
 void phylink_stop(struct phylink *);
 
 void phylink_suspend(struct phylink *pl, bool mac_wol);
+void phylink_prepare_resume(struct phylink *pl);
 void phylink_resume(struct phylink *pl);
 
 void phylink_ethtool_get_wol(struct phylink *, struct ethtool_wolinfo *);