[PATCH] serial: omap: fix the overrun case

[balbi@ti.com (Felipe Balbi)]

On Fri, Sep 21, 2012 at 03:52:56PM +0530, Shubhrajyoti D 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.

Very nice patch but I think commit log can be a bit more verbose.

Please make the problem a little clearer. Why do we even get that
interrupt fired if BRK_ERROR_BITS aren't set ?

> Signed-off-by: Shubhrajyoti D <shubhrajyoti@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))
> +		return;
> +
> +	if (likely(lsr & UART_LSR_DR))
> +		ch = serial_in(up, UART_RX);

Maybe add a comment before this condition stating why this character
read is necessary ?

-- 
balbi
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