Using mii-tool with e1000e driver results in:
SIOCGMIIREG on eth0 failed: Input/output error

Problem is in show_basic_mii() where the loop
    for (i = 0; i < ((verbose > 1) ? 32 : MII_BASIC_MAX); i++)
        mii_val[i] = mdio_read(sock, i);
checks all MII registers from 0x00 to 0x07 (or to 0x1F in verbose mode).
But there's no register with 0x07 value.

For more details see:
https://bugzilla.redhat.com/show_bug.cgi?id=491358#c1

Solution is to check only defined MII registers.

Also the "mii.h" is actually a duplicate of <linux/mii.h>.