[PATCH] serial: omap: fix the overrun case

[Poddar, Sourav]

Hi,

On Fri, Sep 21, 2012 at 3:52 PM, Shubhrajyoti D <shubhrajyoti at ti.com> wrote:
> Overrun also causes an internal flag to be set, which disables further
> reception. Before the next frame can
> be received, the MPU must:
> • Reset the RX FIFO.
> • clear the internal flag.
>
> In the uart mode a dummy read is needed. Add the same.
>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti at ti.com>
> ---
> - functional testing on omap4sdp
> - Verified idle and suspend path hits off on beagle.
>
>  drivers/tty/serial/omap-serial.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index a0d4460..bc22a2b 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -334,6 +334,13 @@ static unsigned int check_modem_status(struct uart_omap_port *up)
>  static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
>  {
>         unsigned int flag;
> +       unsigned char ch = 0;
> +
> +       if (!(lsr & UART_LSR_BRK_ERROR_BITS))
By using this flag, you are trying to take into account not just the
overrun case but also
frame, parity and break condition case as the flag is the OR of all these.

I suppose the commit log should reflect this.
> +               return;
> +
> +       if (likely(lsr & UART_LSR_DR))
> +               ch = serial_in(up, UART_RX);
>
>         up->port.icount.rx++;
>         flag = TTY_NORMAL;
> --
> 1.7.5.4
>