Re: [PATCH V2 3/3] tty: serial: qcom_geni_serial: Fix the UART wakeup issue

[Akash Asthana <akashast@codeaurora.org>]

On 7/24/2020 9:28 AM, satya priya wrote:
> As a part of system suspend we call uart_port_suspend from the
> Serial driver, which calls set_mctrl passing mctrl as NULL. This
> makes RFR high(NOT_READY) during suspend.
>
> Due to this BT SoC is not able to send wakeup bytes to UART during
> suspend. Included if check for non-suspend case to keep RFR low
> during suspend.


Reviewed-by: Akash Asthana <akashast@codeaurora.org>

> Signed-off-by: satya priya <skakit@codeaurora.org>
> ---
> Changes in V2:
>   - This patch fixes the UART flow control issue during suspend.
>     Newly added in V2.
>
>   drivers/tty/serial/qcom_geni_serial.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
> index 07b7b6b..7108dfc 100644
> --- a/drivers/tty/serial/qcom_geni_serial.c
> +++ b/drivers/tty/serial/qcom_geni_serial.c
> @@ -242,7 +242,7 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
>   	if (mctrl & TIOCM_LOOP)
>   		port->loopback = RX_TX_CTS_RTS_SORTED;
>   
> -	if (!(mctrl & TIOCM_RTS))
> +	if ((!(mctrl & TIOCM_RTS)) && (!(uport->suspended)))
>   		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
>   	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
>   }

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