[PATCH v3 1/9] serial: qcom-geni: fix polled console initialisation

From: Johan Hovold
Date: Wed Oct 09 2024 - 10:52:03 EST


The polled console (KGDB/KDB) implementation must not call port setup
unconditionally as the port may already be in use by the console or a
getty.

Only make sure that the receiver is enabled, but do not enable any
device interrupts.

Fixes: d8851a96ba25 ("tty: serial: qcom-geni-serial: Add a poll_init() function")
Cc: stable@xxxxxxxxxxxxxxx # 6.4
Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
---
drivers/tty/serial/qcom_geni_serial.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 6f0db310cf69..c237c9d107cd 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -147,6 +147,7 @@ static struct uart_driver qcom_geni_uart_driver;

static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport);
+static int qcom_geni_serial_port_setup(struct uart_port *uport);

static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport)
{
@@ -395,6 +396,23 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
writel(c, uport->membase + SE_GENI_TX_FIFOn);
qcom_geni_serial_poll_tx_done(uport);
}
+
+static int qcom_geni_serial_poll_init(struct uart_port *uport)
+{
+ struct qcom_geni_serial_port *port = to_dev_port(uport);
+ int ret;
+
+ if (!port->setup) {
+ ret = qcom_geni_serial_port_setup(uport);
+ if (ret)
+ return ret;
+ }
+
+ if (!qcom_geni_serial_secondary_active(uport))
+ geni_se_setup_s_cmd(&port->se, UART_START_READ, 0);
+
+ return 0;
+}
#endif

#ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE
@@ -1582,7 +1600,7 @@ static const struct uart_ops qcom_geni_console_pops = {
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = qcom_geni_serial_get_char,
.poll_put_char = qcom_geni_serial_poll_put_char,
- .poll_init = qcom_geni_serial_port_setup,
+ .poll_init = qcom_geni_serial_poll_init,
#endif
.pm = qcom_geni_serial_pm,
};
--
2.45.2