At 100Mbps link speed on eth1 and eth2 interfaces when configured with ethtool command, ping is no longer able to be completed (100% packet loss) through the hsr interfaces. 

Customer found same issue on SDK 11.0 

Customer also found that there are differences in behavior between configuring link speed to 100Mbps with ethtool command versus bring down link speed due to link partner advertised speed at 100Mbps. When the latter is used, there doesn't seem to be any particular issue with ping. 

Regular (non-HSR) traffic at 100Mbps through the PRU-ICSSG interfaces work fine without packet loss, indicating most likely something to do with the firmware at 100Mbps.

07/8/25 Update, tested on SDK 11.0:

When the below sequence is used, ping fails at 100M:

1. Set 100M on eth1 and eth2
2. Bring up eth interfaces if they are not brought up yet
3. Set up hsr offload + cut-through
4. Ping from EVM1 to EVM3

When a different sequence is used, ping passes at 100M:

1. Ensure eth interfaces are up if they are not brought up yet
2. Set up hsr offload + cut-through
3. Set 100M on eth1 & eth2
4. Ping EVM1 to EVM3

07/21/25 Update, tested on SDK 11.1:

SDK 11.1 should include the below changes for firmware and driver

[missing ICSSG buffer allocation patches integrated into SDK 11.1? https://lore.kernel.org/all/20250717094220.546388-1-h-mittal1@ti.com/ ]

https://git.ti.com/cgit/processor-firmware/ti-linux-firmware/commit/?h=ti-linux-firmware&id=29d948b63a48ec4ff7883d2e246dfb7b6c8153aa 

https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/commit/drivers/net/ethernet/ti/icssg?h=ti-linux-6.12.y&id=7d326261bb2afd77f3fe378e3d42e1c595bc8206 

But still fails this 100Mbps ping test see log in link below:

https://gist.github.com/dao-qiu/75558e9b50459104fa0549d499942441 

I tried to obtain PA_stats 0x300a7000 to 0x300a7300,

Fix merged in upstream - https://lore.kernel.org/all/175468140625.242168.262371954250110213.git-patchwork-notify@kernel.org/