On 25/03/2021 08:12, Joakim Zhang wrote:

...

quoted

quoted

quoted

quoted

You mean one of your boards? Does other boards with STMMAC can work

fine?

We have two devices with the STMMAC and one works OK and the other

fails.

quoted

quoted

They are different generation of device and so there could be some
architectural differences which is causing this to only be seen on one device.

It's really strange, but I also don't know what architectural differences could

affect this. Sorry.

I realised that for the board which fails after this change is made, it
has the IOMMU enabled. The other board does not at the moment (although
work is in progress to enable). If I add 'iommu.passthrough=1' to
cmdline for the failing board, then it works again. So in my case, the
problem is linked to the IOMMU being enabled.

Does you platform enable the IOMMU?

Thanks
Jon

-- 
nvpublic