illumos gate

There are a few drivers which errantly return EINVAL instead of ENOTSUP in their *_m_getprop() and *_m_setprop() GLD callbacks. While this doesn't break anything functionally, this does have at least one visible side effect in, for example, `dladm show-linkprop` output where unused properties will feature a ? in their disposition fields rather than an expected --, and if selecting a specific property to fetch with dladm show-linkprop -p <propery> you will also receive a warning: dladm: warning: cannot get link property 'en_40gfdx_cap' for igb0: invalid argument

For example, the igb driver is one such driver which does this:

[daleg@devohat]~$ dladm show-linkprop -p en_40gfdx_cap igb0 
LINK         PROPERTY        PERM VALUE          DEFAULT        POSSIBLE
dladm: warning: cannot get link property 'en_40gfdx_cap' for igb0: invalid argument
igb0         en_40gfdx_cap   ?    ?              0              1,0

Versus the e1000g driver, which correctly returns ENOTSUP for properties it doesn't care about:

[daleg@bloody]~$ dladm show-linkprop -p en_40gfdx_cap e1000g0
LINK         PROPERTY        PERM VALUE          DEFAULT        POSSIBLE
e1000g0      en_40gfdx_cap   --   --             0              1,0

Setting link properties also befalls the same issue w.r.t. EINVAL vs. ENOTSUP:

Returning EINVAL:

root@devohat:/root# dladm set-linkprop -p en_40gfdx_cap=1 igb0   
dladm: warning: cannot set link property 'en_40gfdx_cap' on 'igb0': invalid argument

Vs. returning ENOTSUP:

[root@r151016]~# dladm set-linkprop -p en_40gfdx_cap=1 e1000g0
dladm: warning: invalid link property 'en_40gfdx_cap'

So far, I've spotted the following drivers which errantly return EINVAL instead of ENOTSUP in either _getprop, _setprop, or both:
igb
ixgbe
hxge

There may be others; as this was not an exhaustive search.