Linux Serial subsystem development
 help / color / mirror / Atom feed
From: Aniket Randive <aniket.randive@oss.qualcomm.com>
To: gregkh@linuxfoundation.org, jirislaby@kernel.org
Cc: praveen.talari@oss.qualcomm.com, bryan.odonoghue@linaro.org,
	viken.dadhaniya@oss.qualcomm.com, quic_zongjian@quicinc.com,
	krzk@kernel.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	Aniket Randive <aniket.randive@oss.qualcomm.com>
Subject: [PATCH V1] serial: qcom_geni: Disable closing_wait for console to prevent shutdown timeout
Date: Mon,  6 Jul 2026 15:07:49 +0530	[thread overview]
Message-ID: <20260706093749.836121-1-aniket.randive@oss.qualcomm.com> (raw)

During system power-off, systemd closes the console UART and blocks in
tty_wait_until_sent() waiting for pending TX completion before
uart_shutdown() can cancel pending TX operations. With the default
closing_wait of 30s, this causes a watchdog reset when systemd is
responsible for watchdog feeding.

Set closing_wait to ASYNC_CLOSING_WAIT_NONE in startup() for console
ports to bypass tty_wait_until_sent() on close, allowing uart_shutdown()
to cancel TX commands cleanly. This change doesn't impact regular ports
functionality.

Signed-off-by: Aniket Randive <aniket.randive@oss.qualcomm.com>
---
 drivers/tty/serial/qcom_geni_serial.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 7ead87b4eb65..3d3bed0923eb 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1245,6 +1245,7 @@ static int qcom_geni_serial_startup(struct uart_port *uport)
 {
 	int ret;
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
+	struct tty_port *tport = &uport->state->port;
 
 	if (!port->setup) {
 		ret = qcom_geni_serial_port_setup(uport);
@@ -1252,6 +1253,13 @@ static int qcom_geni_serial_startup(struct uart_port *uport)
 			return ret;
 	}
 
+	/*
+	 * Skip the close-time transmit drain for console ports so that
+	 * shutdown can proceed without waiting for pending TX completion.
+	 */
+	if (uart_console(uport))
+		tport->closing_wait = ASYNC_CLOSING_WAIT_NONE;
+
 	uart_port_lock_irq(uport);
 	qcom_geni_serial_start_rx(uport);
 	uart_port_unlock_irq(uport);
-- 
2.34.1


                 reply	other threads:[~2026-07-06  9:38 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260706093749.836121-1-aniket.randive@oss.qualcomm.com \
    --to=aniket.randive@oss.qualcomm.com \
    --cc=bryan.odonoghue@linaro.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jirislaby@kernel.org \
    --cc=krzk@kernel.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-serial@vger.kernel.org \
    --cc=praveen.talari@oss.qualcomm.com \
    --cc=quic_zongjian@quicinc.com \
    --cc=viken.dadhaniya@oss.qualcomm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox