From: Yan Wang <rk.code@xxxxxxxxxxx> [ Upstream commit 35226750f7ab9d49140d95bc7d38a2a9b0f4fdfc ] 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: b3dcb3127786 ("net: stmmac: correct clocks enabled in stmmac_vlan_rx_kill_vid()") Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> Signed-off-by: Yan Wang <rk.code@xxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index a3bd5396c2f87..179f8d196c890 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -6283,6 +6283,10 @@ 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; @@ -6290,16 +6294,18 @@ 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) -- 2.39.2