Re: serial flow control appears broken

Paul Fulghum
2007-07-27T19:08:22Z

On Fri, 2007-07-27 at 12:22 -0600, Robert Hancock wrote:

> In this situation, though, it appears it's not the TTY buffers that are
> filling but the UART's own buffer. I would think this must be caused by
> some kind of interrupt latency that results in not draining the FIFO in
> time.

You are right, this error is output when the character flag TTY_OVERRUN
is encountered by n_tty.c which should be set by the driver
in response to a hardware FIFO overrun (not an ldisc buffer overrun).

I can't see anyplace in serial_core.c or 8250.c that sets TTY_OVERRUN.

--
Paul Fulghum
Microgate Systems, Ltd