Ah, right. Now it makes sense. You didn't mention what SFP you are trying to use, and I for one have assumed that it simply was a non-Intel SR or LR. The fact that this is a weird SFP makes all the difference.
Looking at the driver, I see that many unusual SFPs will end up with that error regardless of the allow_unsupported_sfp values, as you are experiencing. The error code which translates into that error messsage has actually two different meanings:
- LR or SR SFP+ with unsupported vendor code,
- any SFP with unexpected eeprom contents
The first meaning is an artificial incompatiblity wich can be removed by setting allow_unsupported_sfp. The second meaning might be a real incomatibility. Hard to know. It is not affected by any driver setting.
But you can obviously patch the driver if you want to test that. You'll have to figure out exactly where it ends up returning IXGBE_ERR_SFP_NOT_SUPPORTED to the probe, and then change that code. I assume it's one of the tests in ixgbe_identify_sfp_module_generic() :
But it might also be in ixgbe_get_sfp_init_sequence_offsets(). Or somewhere else I am missing.
I suggest starting by turning on all debugging in the driver. But looking at the code, you'll probably have ot add a few more debug printk's to get any useful info out of it.
No, you cannot expect an ONT SFP to "just work". That's not just another SFP.