• Changming Huang's avatar
    fsl/usb: Workarourd for USB erratum-A005697 · 9d4b8270
    Changming Huang authored
    The EHCI specification states the following in the SUSP bit description:
    In the Suspend state, the port is sensitive to resume detection.
    Note that the bit status does not change until the port is suspended and
    that there may be a delay in suspending a port if there is a transaction
    currently in progress on the USB.
    
    However, in NXP USBDR controller, the PORTSCx[SUSP] bit changes immediately
    when the application sets it and not when the port is actually suspended.
    
    So the application must wait for at least 10 milliseconds after a port
    indicates that it is suspended, to make sure this port has entered
    suspended state before initiating this port resume using the Force Port
    Resume bit. This bit is for NXP controller, not EHCI compatible.
    Signed-off-by: default avatarChangming Huang <jerry.huang@nxp.com>
    Signed-off-by: default avatarRamneek Mehresh <ramneek.mehresh@nxp.com>
    Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    9d4b8270
fsl_devices.h 4.32 KB