From 2de1066dc859036f35fefd52483b2f3712462971 Mon Sep 17 00:00:00 2001 From: Konrad Dybcio Date: Wed, 19 Aug 2026 18:46:47 +0200 Subject: [PATCH] serial: qcom-geni: keep registered console runtime active Commit aee1f94dab13 ("serial: qcom-geni: remove .pm callback, use runtime PM in startup/shutdown") moved runtime PM references from the serial-core PM callback to the port startup and shutdown callbacks. The serial core used to leave the console port powered after registration, but after the callback was removed the temporary probe reference is always released. Console writes are not tied to an open TTY and can run from contexts which cannot resume the device, so a runtime-suspended console can stall. This was observed on a Qualcomm X1E80100 CRD device, as the boot console became flakey across boots. Acquire a runtime PM reference when the console is set up and release it through the console exit callback. This keeps the device active only while the console is registered and balances the reference when the console is disabled or re-enabled through sysfs. Fixes: aee1f94dab13 ("serial: qcom-geni: remove .pm callback, use runtime PM in startup/shutdown") Assisted-by: LLM Signed-off-by: Konrad Dybcio Reviewed-by: Abel Vesa Tested-by: David Heidelberg # OnePlus 6T (sdm845) Link: https://patch.msgid.link/20260819-topic-geni_console_poweredoff-v1-1-7f7bb3aad8da@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/qcom_geni_serial.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 82cca5867cbe..a851b8f0ef04 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1626,16 +1626,37 @@ static int qcom_geni_console_setup(struct console *co, char *options) if (unlikely(!uport->membase)) return -ENXIO; + ret = pm_runtime_resume_and_get(uport->dev); + if (ret < 0) + return ret; + if (!port->setup) { ret = qcom_geni_serial_port_setup(uport); - if (ret) + if (ret) { + pm_runtime_put_sync(uport->dev); return ret; + } } if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); - return uart_set_options(uport, co, baud, parity, bits, flow); + ret = uart_set_options(uport, co, baud, parity, bits, flow); + if (ret) + pm_runtime_put_sync(uport->dev); + + return ret; +} + +static int qcom_geni_console_exit(struct console *co) +{ + struct qcom_geni_serial_port *port; + + port = get_port_from_line(co->index, true, NULL); + if (IS_ERR(port)) + return PTR_ERR(port); + + return pm_runtime_put_sync(port->uport.dev); } static void qcom_geni_serial_earlycon_write(struct console *con, @@ -1752,6 +1773,7 @@ static struct console cons_ops = { .device_unlock = qcom_geni_serial_console_device_unlock, .device = uart_console_device, .setup = qcom_geni_console_setup, + .exit = qcom_geni_console_exit, .flags = CON_PRINTBUFFER | CON_NBCON, .index = -1, .data = &qcom_geni_console_driver,