serial_core: Update buffer overrun statistics.

Currently, serial drivers don't report buffer overruns. When a buffer overrun
occurs, tty_insert_flip_char returns 0, and no attempt is made to insert that
same character again (i.e. it is lost). This patch reports buffer overruns via
the buf_overrun field in the port's icount structure.

Signed-off-by: Corbin Atkinson <corbin.atkinson@ni.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Corbin Atkinson 2012-05-04 12:35:10 -05:00 committed by Greg Kroah-Hartman
parent b1d679afd7
commit 642180871b

View file

@ -2526,14 +2526,16 @@ void uart_insert_char(struct uart_port *port, unsigned int status,
struct tty_struct *tty = port->state->port.tty;
if ((status & port->ignore_status_mask & ~overrun) == 0)
tty_insert_flip_char(tty, ch, flag);
if (tty_insert_flip_char(tty, ch, flag) == 0)
++port->icount.buf_overrun;
/*
* Overrun is special. Since it's reported immediately,
* it doesn't affect the current character.
*/
if (status & ~port->ignore_status_mask & overrun)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
++port->icount.buf_overrun;
}
EXPORT_SYMBOL_GPL(uart_insert_char);