Comment # 67 on bug 944978 from Takashi Iwai

Now looking more closely at the code again, I noticed that I have misunderstood
the upstream fix.  I thought somehow it changed the default behavior of
rtl8821ae, but instead, it just adds the new option int_clear.  So, it's
obvious that the previous tentative fix works while the new one doesn't.  The
previous fix enabled int_clear behavior forcibly.

To defense myself, the option description is confusing, too.  The default value
of int_clear is 1 although it's mentioned to be 0.  And yet, if int_clear is 0,
the driver clears interrupts before enable.  Hmm...