• Jim Lin's avatar
    usb: xhci: Add Clear_TT_Buffer · ef513be0
    Jim Lin authored
    USB 2.0 specification chapter 11.17.5 says "as part of endpoint halt
    processing for full-/low-speed endpoints connected via a TT, the host
    software must use the Clear_TT_Buffer request to the TT to ensure
    that the buffer is not in the busy state".
    
    In our case, a full-speed speaker (ConferenceCam) is behind a high-
    speed hub (ConferenceCam Connect), sometimes once we get STALL on a
    request we may continue to get STALL with the folllowing requests,
    like Set_Interface.
    
    Here we invoke usb_hub_clear_tt_buffer() to send Clear_TT_Buffer
    request to the hub of the device for the following Set_Interface
    requests to the device to get ACK successfully.
    Signed-off-by: default avatarJim Lin <jilin@nvidia.com>
    Acked-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    ef513be0
xhci.h 84.2 KB