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    usb: hub: Per-port setting to use old enumeration scheme · 25244227
    Nicolas Boichat 提交于
    The "old" enumeration scheme is considerably faster (it takes
    ~244ms instead of ~356ms to get the descriptor).
    
    It is currently only possible to use the old scheme globally
    (/sys/module/usbcore/parameters/old_scheme_first), which is not
    desirable as the new scheme was introduced to increase compatibility
    with more devices.
    
    However, in our case, we care about time-to-active for a specific
    USB device (which we make the firmware for), on a specific port
    (that is pogo-pin based: not a standard USB port). This new
    sysfs option makes it possible to use the old scheme on a single
    port only.
    Signed-off-by: NNicolas Boichat <drinkcat@chromium.org>
    Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    25244227
hub.h 4.7 KB