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    Subject[013/262] serial: pxa: work around for errata #20
    3.0-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Marcus Folkesson <marcus.folkesson@gmail.com>

    commit e44aabd649c80e8be16ede3ed3cbff6fb2561ca9 upstream.

    Errata E20: UART: Character Timeout interrupt remains set under certain
    software conditions.

    Implication: The software servicing the UART can be trapped in an infinite loop.

    Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/tty/serial/pxa.c | 20 ++++++++++++++++++++
    1 file changed, 20 insertions(+)

    --- a/drivers/tty/serial/pxa.c
    +++ b/drivers/tty/serial/pxa.c
    @@ -100,6 +100,16 @@ static inline void receive_chars(struct
    int max_count = 256;

    do {
    + /* work around Errata #20 according to
    + * Intel(R) PXA27x Processor Family
    + * Specification Update (May 2005)
    + *
    + * Step 2
    + * Disable the Reciever Time Out Interrupt via IER[RTOEI]
    + */
    + up->ier &= ~UART_IER_RTOIE;
    + serial_out(up, UART_IER, up->ier);
    +
    ch = serial_in(up, UART_RX);
    flag = TTY_NORMAL;
    up->port.icount.rx++;
    @@ -156,6 +166,16 @@ static inline void receive_chars(struct
    *status = serial_in(up, UART_LSR);
    } while ((*status & UART_LSR_DR) && (max_count-- > 0));
    tty_flip_buffer_push(tty);
    +
    + /* work around Errata #20 according to
    + * Intel(R) PXA27x Processor Family
    + * Specification Update (May 2005)
    + *
    + * Step 6:
    + * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
    + */
    + up->ier |= UART_IER_RTOIE;
    + serial_out(up, UART_IER, up->ier);
    }

    static void transmit_chars(struct uart_pxa_port *up)



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