Le 09/12/2014 14:31, Cyrille Pitchen a écrit :
> atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls
> clk_disable_unprepare() to disable the peripheral clock before returning.
>
> Later atmel_serial_probe() accesses some I/O registers such as the Mode and
> Control registers for RS485 support then the Name and Version registers, through a call to
> atmel_get_ip_name(), but at that moment the peripheral clock was still
> disabled.
>
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
and you can add also:
Cc: <stable@xxxxxxxxxxxxxxx> # 3.12+
> ---
> drivers/tty/serial/atmel_serial.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 756f567..c6621dc 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -2596,6 +2596,12 @@ static int atmel_serial_probe(struct platform_device *pdev)
> device_init_wakeup(&pdev->dev, 1);
> platform_set_drvdata(pdev, port);
>
> + /*
> + * The peripheral clock has been disabled by atmel_init_port():
> + * enable it before accessing I/O registers
> + */
> + clk_prepare_enable(port->clk);
> +
> if (rs485_enabled) {
> UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
> UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
> @@ -2606,6 +2612,12 @@ static int atmel_serial_probe(struct platform_device *pdev)
> */
> atmel_get_ip_name(&port->uart);
>
> + /*
> + * The peripheral clock can now safely be disabled till the port
> + * is used
> + */
> + clk_disable_unprepare(port->clk);
> +
> return 0;
>
> err_add_port:
>
--
Nicolas Ferre
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