[V2] drivers/tty/serial/qcom-geni-serial: Do stop_rx in suspend path for console if console_suspend is disabled

From: Vijaya Krishna Nivarthi
Date: Wed Apr 06 2022 - 07:39:45 EST

For the case of console_suspend disabled, if back to back suspend/resume
test is executed, at the end of test, sometimes console would appear to
be frozen not responding to input. This would happen because, for
console_suspend disabled, suspend/resume routines only turn resources
off/on but don't do a port close/open.
As a result, during resume, some rx transactions come in before system is
ready, malfunction of rx happens in turn resulting in console appearing
to be stuck.

Do a stop_rx in suspend sequence to prevent this. start_rx is already
present in resume sequence as part of call to set_termios which does a

Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@xxxxxxxxxxx>
drivers/tty/serial/qcom_geni_serial.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 1543a60..6f767c7 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1481,6 +1481,10 @@ static int __maybe_unused qcom_geni_serial_sys_suspend(struct device *dev)
struct uart_port *uport = &port->uport;
struct qcom_geni_private_data *private_data = uport->private_data;

+ /* do a stop_rx here, start_rx is handled in uart_resume_port by call to setermios */
+ if (!console_suspend_enabled && uart_console(uport))
+ uport->ops->stop_rx(uport);
* This is done so we can hit the lowest possible state in suspend
* even with no_console_suspend
Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation.