Commit 35226750 authored by Yan Wang's avatar Yan Wang Committed by David S. Miller
Browse files

net: stmmac:fix system hang when setting up tag_8021q VLAN for DSA ports 



The system hang because of dsa_tag_8021q_port_setup()->
				stmmac_vlan_rx_add_vid().

I found in stmmac_drv_probe() that cailing pm_runtime_put()
disabled the clock.

First, when the kernel is compiled with CONFIG_PM=y,The stmmac's
resume/suspend is active.

Secondly,stmmac as DSA master,the dsa_tag_8021q_port_setup() function
will callback stmmac_vlan_rx_add_vid when DSA dirver starts. However,
The system is hanged for the stmmac_vlan_rx_add_vid() accesses its
registers after stmmac's clock is closed.

I would suggest adding the pm_runtime_resume_and_get() to the
stmmac_vlan_rx_add_vid().This guarantees that resuming clock output
while in use.

Fixes: b3dcb312 ("net: stmmac: correct clocks enabled in stmmac_vlan_rx_kill_vid()")
Reviewed-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Signed-off-by: default avatarYan Wang <rk.code@outlook.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d8bb3824

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

+9 −3
Original line number Diff line number Diff line
@@ -6377,6 +6377,10 @@ static int stmmac_vlan_rx_add_vid(struct net_device *ndev, __be16 proto, u16 vid 
	bool is_double = false;

	int ret;



	ret = pm_runtime_resume_and_get(priv->device);

	if (ret < 0)

		return ret;



	if (be16_to_cpu(proto) == ETH_P_8021AD)

		is_double = true;
@@ -6384,16 +6388,18 @@ static int stmmac_vlan_rx_add_vid(struct net_device *ndev, __be16 proto, u16 vid 
	ret = stmmac_vlan_update(priv, is_double);

	if (ret) {

		clear_bit(vid, priv->active_vlans);

		return ret;

		goto err_pm_put;

	}



	if (priv->hw->num_vlan) {

		ret = stmmac_add_hw_vlan_rx_fltr(priv, ndev, priv->hw, proto, vid);

		if (ret)

			return ret;

			goto err_pm_put;

	}

err_pm_put:

	pm_runtime_put(priv->device);



	return 0;

	return ret;

}



static int stmmac_vlan_rx_kill_vid(struct net_device *ndev, __be16 proto, u16 vid)