[PATCH v3.18] net: fec: introduce fec_ptp_stop and use in probe fail path

[Guenter Roeck <linux@roeck-us.net>]

From: Lucas Stach <l.stach@pengutronix.de>

[ upstream commit 32cba57ba74be58589aeb4cb6496183e46a5e3e5 ]

This function frees resources and cancels delayed work item that
have been initialized in fec_ptp_init().

Use this to do proper error handling if something goes wrong in
probe function after fec_ptp_init has been called.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[groeck: backport: context changes in .../fec_main.c]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
Not really sure if I should send this one to David or Greg, since v3.18 is no
longer officially supported, so I am sending it to both. Sorry for the noise.

This patch fixes a crash seen when running sabrelite images in a version
of qemu which fixes https://bugs.launchpad.net/qemu/+bug/1753309.

 drivers/net/ethernet/freescale/fec.h      |  1 +
 drivers/net/ethernet/freescale/fec_main.c |  5 ++---
 drivers/net/ethernet/freescale/fec_ptp.c  | 10 ++++++++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 9af296a1ca99..c16b6deff5ea 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -546,6 +546,7 @@ struct fec_enet_private {
 };
 
 void fec_ptp_init(struct platform_device *pdev);
+void fec_ptp_stop(struct platform_device *pdev);
 void fec_ptp_start_cyclecounter(struct net_device *ndev);
 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr);
 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr);
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 065a7616e961..f1224c2d112a 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3312,6 +3312,7 @@ failed_register:
 failed_mii_init:
 failed_irq:
 failed_init:
+	fec_ptp_stop(pdev);
 	if (fep->reg_phy)
 		regulator_disable(fep->reg_phy);
 failed_regulator:
@@ -3331,14 +3332,12 @@ fec_drv_remove(struct platform_device *pdev)
 	struct net_device *ndev = platform_get_drvdata(pdev);
 	struct fec_enet_private *fep = netdev_priv(ndev);
 
-	cancel_delayed_work_sync(&fep->time_keep);
 	cancel_work_sync(&fep->tx_timeout_work);
+	fec_ptp_stop(pdev);
 	unregister_netdev(ndev);
 	fec_enet_mii_remove(fep);
 	if (fep->reg_phy)
 		regulator_disable(fep->reg_phy);
-	if (fep->ptp_clock)
-		ptp_clock_unregister(fep->ptp_clock);
 	fec_enet_clk_enable(ndev, false);
 	of_node_put(fep->phy_node);
 	free_netdev(ndev);
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index 992c8c3db553..9b2dcf4261a5 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -620,6 +620,16 @@ void fec_ptp_init(struct platform_device *pdev)
 	schedule_delayed_work(&fep->time_keep, HZ);
 }
 
+void fec_ptp_stop(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct fec_enet_private *fep = netdev_priv(ndev);
+
+	cancel_delayed_work_sync(&fep->time_keep);
+	if (fep->ptp_clock)
+		ptp_clock_unregister(fep->ptp_clock);
+}
+
 /**
  * fec_ptp_check_pps_event
  * @fep: the fec_enet_private structure handle
-- 
2.7.4