serial: qcom-geni: fix polled console initialisation

commit 4bef7c6 upstream.

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: d8851a9 ("tty: serial: qcom-geni-serial: Add a poll_init() function")
Cc: stable@vger.kernel.org	# 6.4
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20241009145110.16847-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jhovold

drivers/tty/serial/qcom_geni_serial.c

@@ -146,6 +146,7 @@ static struct uart_driver qcom_geni_console_driver;
 static struct uart_driver qcom_geni_uart_driver;
 
 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)
 {
@@ -393,6 +394,23 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport,
 	writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR);
 	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
@@ -1564,7 +1582,7 @@ 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,
 };