Re: [PATCH V5 4/4] tty: serial: qcom_geni_serial: Fix the UART wakeup issue

[Bjorn Andersson]

On Thu 10 Sep 12:53 UTC 2020, satya priya wrote:

> As a part of system suspend uart_port_suspend is called from the
> Serial driver, which calls set_mctrl passing mctrl as 0. This
> makes RFR high(NOT_READY) during suspend.
> 
> Due to this BT SoC is not able to send wakeup bytes to UART during
> suspend. Include if check for non-suspend case to keep RFR low
> during suspend.
> 

Seems reasonable.

Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

> Signed-off-by: satya priya <skakit@xxxxxxxxxxxxxx>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Greg, I don't see this depending on anything else, will you pick this
patch through your tree? I will take the dts patches through the qcom
tree.

Regards,
Bjorn

> Reviewed-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
> ---
> Changes in V2:
>  - This patch fixes the UART flow control issue during suspend.
>    Newly added in V2.
> 
> Changes in V3:
>  - As per Matthias's comment removed the extra parentheses.
> 
> Changes in V4:
>  - No change.
> 
> Changes in V5:
>  - As per Matthias comment, fixed nit-pick in commit text.
> 
>  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 3aa29d2..bc63c54 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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