1:  e635b4b532b3 ! 1:  02092a5cae93 mac80211: fix ieee80211_set_antenna() return value
    @@ Metadata
      ## Commit message ##
         mac80211: fix ieee80211_set_antenna() return value
     
    -    To set up antenna the device must be disabled, "not started".
    -    So return -EBUSY instead of -EOPNOTSUPP
    +    Actually ieee80211_set_antenna() returns -EOPNOTSUPP in case the device is
    +    "started". That is confusing. Return -EBUSY instead. That makes clear that
    +    the device must be stopped beforehand.
    +
    +    Given an active wifi device:
     
         $ iw phy0 set antenna 0x3
         command failed: Operation not supported (-95)
    @@ Commit message
         expected output:
         command failed: Device or resource busy (-16)
     
    +    drv_set_antenna() later on will check if the driver supports it.
    +
    +    Fixes: 15d967532148 ("mac80211: Add antenna configuration")
         Signed-off-by: Christoph Rudorff <chris@rudorff.com>
     
      ## net/mac80211/cfg.c ##