Regression v5.12-rc3: net: stmmac: re-init rx buffers when mac resume back

From: Jon Hunter
Date: Wed Mar 24 2021 - 06:52:24 EST


Hi Joakim,

Starting with v5.12-rc3 I noticed that one of our boards, Tegra186
Jetson TX2, was not long resuming from suspend. Bisect points to commit
9c63faaa931e ("net: stmmac: re-init rx buffers when mac resume back")
and reverting this on top of mainline fixes the problem.

Interestingly, the board appears to partially resume from suspend and I
see ethernet appear to resume ...

dwc-eth-dwmac 2490000.ethernet eth0: configuring for phy/rgmii link
mode
dwmac4: Master AXI performs any burst length
dwc-eth-dwmac 2490000.ethernet eth0: No Safety Features support found
dwc-eth-dwmac 2490000.ethernet eth0: Link is Up - 1Gbps/Full - flow
control rx/tx

I don't see any crash, but then it hangs at some point. Please note that
this board is using NFS for mounting the rootfs.

Let me know if there is any more info I can provide or tests I can run.

Thanks
Jon