net: stmmac:fix system hang when setting up tag_8021q VLAN for DSA ports
authorYan Wang <rk.code@outlook.com>
Wed, 19 Apr 2023 14:13:46 +0000 (22:13 +0800)
committerDavid S. Miller <davem@davemloft.net>
Fri, 21 Apr 2023 10:44:35 +0000 (11:44 +0100)
commit35226750f7ab9d49140d95bc7d38a2a9b0f4fdfc
treea89616953b7484b27e3f2f1f90075e78ac20e4a0
parentd8bb382419230cf626a527eeb55efae0c56039fb
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: b3dcb3127786 ("net: stmmac: correct clocks enabled in stmmac_vlan_rx_kill_vid()")
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Yan Wang <rk.code@outlook.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c