• Johannes Berg's avatar
    iwlwifi: handle unicast PS buffering · 6ab10ff8
    Johannes Berg authored
    Using the new mac80211 functionality, this makes
    iwlwifi handle unicast PS buffering correctly.
    The device works like this:
    
     * when a station goes to sleep, the microcode notices
       this and marks the station as asleep
     * when the station is marked asleep, the microcode
       refuses to transmit to the station and rejects all
       frames queued to it with the failure status code
       TX_STATUS_FAIL_DEST_PS (a previous patch handled
       this correctly)
     * when we need to send frames to the station _although_
       it is asleep, we need to tell the ucode how many,
       and this is asynchronous with sending so we cannot
       just send the frames, we need to wait for all other
       frames to be flushed, and then update the counter
       before sending out the poll response frames. This
       is handled partially in the driver and partially in
       mac80211.
    
    In order to do all this correctly, we need to
     * keep track of how many frames are pending for each
       associated client station (avoid doing it for other
       stations to avoid the atomic ops)
     * tell mac80211 that we driver-block the PS status
       while there are still frames pending on the queues,
       and once they are all rejected (due to the dest sta
       being in PS) unblock mac80211
    Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
    Signed-off-by: default avatarReinette Chatre <reinette.chatre@intel.com>
    Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
    6ab10ff8
iwl-sta.h 3.13 KB