Re: [PATCH net 3/3] net: stmmac: check if interface is running before TC block setup

[Sebastian Basierski <sebastian.basierski@intel.com>]

On 9/5/2025 3:56 AM, Jakub Kicinski wrote:
> On Thu, 4 Sep 2025 21:01:49 +0200 Sebastian Basierski wrote:
>> On 9/1/2025 10:03 PM, Jakub Kicinski wrote:
>>> More context would be useful. What's the user-visible behavior before
>>> and after? Can the device handle installing the filters while down?
>>> Is it just an issue of us restarting the queues when we shouldn't?
>> Before this patch driver couldn't be unloaded with tc filter applied.
>>
>> Running those commands is enough to reproduce the issue:
>>     tc qdisc add dev enp0s29f2 ingress
>>     tc filter add dev enp0s29f2 ingress protocol all prio 1 u32
>>     rmmod dwmac_intel
>>
>> in effect module would not unload.
> Makes sense. Could you also confirm that the offload doesn't in fact
> work if set up when device is down? I think block setup is when qdisc
> is installed?
>
> ip link set dev $x down
> tc qdisc add dev enp0s29f2 ingress
> ip link set dev $x up
> tc filter add dev enp0s29f2 ingress protocol all prio 1 u32 ...
>
> If it doesn't work we can feel safe we're not breaking anyone's
> scripts, however questionable.
Sorry for late response.
I just checked what you asked for.
   x="enp129s29f0"
   ip link set dev $x down
   tc qdisc add dev $x ingress
   ip link set dev $x up
   tc filter add dev $x ingress protocol ip flower ip_proto 1 action drop
Looks like with and without patch ICMP packets are dropped.