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    Subject[PATCH 4.9 50/72] tty/serial: atmel: fix TX path in atmel_console_write()
    Date
    4.9-stable review patch.  If anyone has any objections, please let me know.

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

    From: Nicolas Ferre <nicolas.ferre@microchip.com>

    commit 497e1e16f45c70574dc9922c7f75c642c2162119 upstream.

    A side effect of 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA
    from transmitting in stop_tx") is that the console can be called with
    TX path disabled. Then the system would hang trying to push charecters
    out in atmel_console_putchar().

    Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
    Fixes: 89d8232411a8 ("tty/serial: atmel_serial: BUG: stop DMA from transmitting in stop_tx")
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/tty/serial/atmel_serial.c | 3 +++
    1 file changed, 3 insertions(+)

    --- a/drivers/tty/serial/atmel_serial.c
    +++ b/drivers/tty/serial/atmel_serial.c
    @@ -2476,6 +2476,9 @@ static void atmel_console_write(struct c
    pdc_tx = atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN;
    atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTDIS);

    + /* Make sure that tx path is actually able to send characters */
    + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN);
    +
    uart_console_write(port, s, count, atmel_console_putchar);

    /*

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