• Zhu Yi's avatar
    mac80211: hardware scan rework · ece8eddd
    Zhu Yi authored
    The scan code in mac80211 makes the software scan assumption in various
    places. For example, we stop the Tx queue during a software scan so that
    all the Tx packets will be queued by the stack. We also drop frames not
    related to scan in the software scan process. But these are not true for
    hardware scan.
    Some wireless hardwares (for example iwl3945/4965) has the ability to
    perform the whole scan process by hardware and/or firmware. The hardware
    scan is relative powerful in that it tries to maintain normal network
    traffic while doing a scan in the background. Some drivers (i.e iwlwifi)
    do provide a way to tune the hardware scan parameters (for example if the
    STA is associated, what's the max time could the STA leave from the
    associated channel, how long the scans get suspended after returning to
    the service channel, etc). But basically this is transparent to the
    stack. mac80211 should not stop Tx queues or drop Rx packets during a
    hardware scan.
    This patch resolves the above problem by spliting the current scan
    indicator local->sta_scanning into local->sta_sw_scanning and
    local->sta_hw_scanning. It then changes the scan related code to be aware
    of hardware scan or software scan in various places. With this patch,
    iwlwifi performs much better in the scan-while-associated condition and
    disable_hw_scan=1 should never be required.
    Cc: Mohamed Abbas <mohamed.abbas@intel.com>
    Cc: Ben Cahill <ben.m.cahill@intel.com>
    Signed-off-by: default avatarZhu Yi <yi.zhu@intel.com>
    Acked-by: default avatarJohannes Berg <johannes@sipsolutions.net>
    Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
ieee80211_i.h 24.9 KB