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

[Florian Fainelli]

On 4/13/2023 7:08 AM, Florian Fainelli wrote:
> 
> 
> On 4/13/2023 6:38 AM, Yan Wang wrote:
>> 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.
>>
>> Signed-off-by: Yan Wang <rk.code at outlook.com>
> 
> You have posted this patch several times now yet not on 
> netdev at vger.kernel or towards the maintainers of the drivers, please 
> consider using scripts/get_maintainer.pl.

Was looking at an older version you did copy the proper recipients.

> 
> While it looks like you are fixing a bug, it would be worthy of 
> providing a suitable Fixes: tag since this is a genuine bugfix. You 
> should also consider providing the target tree: 'net' for bug fixes and 
> 'net-next' for features, and also provide a version counter in the 
> subject 'PATCH v4' or something like that.

-- 
Florian