Patch from Thomas Doerfler <td@imd.m.ISAR.de> to add flow control:

    Some lines for "documentation":
    ======================================
    One thing should be noted: when XON/XOFF is enabled, the serial
    device will always work with one-character buffers, so the interrupt
    load for the CPU might get higer, especially on devices like MC68360
    and MPC860, where the serial channels are capable of using big
    buffers. But, once again, this only happens when XON/XOFF is actually
    selected.

    Please note that the flag IXON is set by default, so outgoing
    XON/XOFF flow control is enabled by default.

    XON/XOFF is controlled using the "standard" fields IXON/IXOFF in the
    termios structure. The termios flag IXANY is not (yet) supported.

    Hardware handshake for the incoming data stream is controlled using
    the standard flag CRTSCTS. If this flag is set, whenever the receive
    buffer is almost full, the driver function "device.stopRemoteTx()" is
    called, when the receive buffer has more space available,
    "device.startRemoteTx()" is called again.  If the driver does not
    provide these interface functions (entries in device structure are
    NULL pointers), then these calls are suppressed.

    Changes of the flow control options during operation should work at
    any time, but this has not been extensively tested.

    No changes to the device driver interface are needed.
    ================================================

    One critical point when using this patch might be, that any BSP using
    this version of termios will now have outgoing flow control enabled
    by default, so the behaviour of these BSPs will change here. The
    option IXON has already been set in older termios by default, but it
    did not work until this patch. Maybe this option should be switched
    off by default, what do you think?

0 files changed, 0 insertions, 0 deletions