3.19-stable review patch. If anyone has any objections, please let me know.
------------------ From: Cyrille Pitchen <[email protected]> commit d4f641876a68d1961e30c202709cc2d484f69f6f upstream. 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 <[email protected]> Acked-by: Nicolas Ferre <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/tty/serial/atmel_serial.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2596,6 +2596,12 @@ static int atmel_serial_probe(struct pla 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 pla */ 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: -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
