On 11 May 2016 at 14:30, Pramod Gurav <pramod.gurav@xxxxxxxxxx> wrote:
> msm_serial driver provides a .pm callback to the serial core to enable
> and disable clock resource in suspend/resume path. This function is
> also called before msm_startup. msm_startup also enables the clocks which
> is not needed. Hence remove the duplcate clock operation from msm_startup
> and msm_shutdown. Same is done in console setup to get rid of duplicate
> clock operation.
>
> Tested on DB410C console.
>
> Signed-off-by: Pramod Gurav <pramod.gurav@xxxxxxxxxx>
> ---
> drivers/tty/serial/msm_serial.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
> index dcde955..73c3217 100644
> --- a/drivers/tty/serial/msm_serial.c
> +++ b/drivers/tty/serial/msm_serial.c
> @@ -959,15 +959,6 @@ static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
> return baud;
> }
>
> -static void msm_init_clock(struct uart_port *port)
> -{
> - struct msm_port *msm_port = UART_TO_MSM(port);
> -
> - clk_prepare_enable(msm_port->clk);
> - clk_prepare_enable(msm_port->pclk);
> - msm_serial_set_mnd_regs(port);
> -}
> -
> static int msm_startup(struct uart_port *port)
> {
> struct msm_port *msm_port = UART_TO_MSM(port);
> @@ -982,7 +973,7 @@ static int msm_startup(struct uart_port *port)
> if (unlikely(ret))
> return ret;
>
> - msm_init_clock(port);
> + msm_serial_set_mnd_regs(port);
Further testing with another UART port made me realize that serial
port does not work after disabling msm_port->clk clock. The RX data
part will be affected.
Confirmed from manual that this clock should never be turned of to
avoid loss of incoming data. Sorry for the noise.
>
> if (likely(port->fifosize > 12))
> rfr_level = port->fifosize - 12;
> @@ -1021,8 +1012,6 @@ static void msm_shutdown(struct uart_port *port)
> if (msm_port->is_uartdm)
> msm_release_dma(msm_port);
>
> - clk_disable_unprepare(msm_port->clk);
> -
> free_irq(port->irq, port);
> }
>
> @@ -1451,7 +1440,7 @@ static int __init msm_console_setup(struct console *co, char *options)
> if (unlikely(!port->membase))
> return -ENXIO;
>
> - msm_init_clock(port);
> + msm_serial_set_mnd_regs(port);
>
> if (options)
> uart_parse_options(options, &baud, &parity, &bits, &flow);
> --
> 1.8.2.1
>
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
