Request the RX mailbox only after initializing the UART data
structures. Otherwise it can rarely happen that the receive
callback is called before the UART is ready.
Fixes: 2d908b38d409 ("serial: Add Tegra Combined UART driver")
Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
---
drivers/tty/serial/tegra-tcu.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/tegra-tcu.c b/drivers/tty/serial/tegra-tcu.c
index 52687c65ad74..4877c54c613d 100644
--- a/drivers/tty/serial/tegra-tcu.c
+++ b/drivers/tty/serial/tegra-tcu.c
@@ -195,13 +195,6 @@ static int tegra_tcu_probe(struct platform_device *pdev)
return err;
}
- tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
- if (IS_ERR(tcu->rx)) {
- err = PTR_ERR(tcu->rx);
- dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
- goto free_tx;
- }
-
#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
/* setup the console */
strcpy(tcu->console.name, "ttyTCU");
@@ -226,7 +219,7 @@ static int tegra_tcu_probe(struct platform_device *pdev)
if (err) {
dev_err(&pdev->dev, "failed to register UART driver: %d\n",
err);
- goto free_rx;
+ goto free_tx;
}
/* setup the port */
@@ -246,6 +239,17 @@ static int tegra_tcu_probe(struct platform_device *pdev)
goto unregister_uart;
}
+ /*
+ * Request RX channel after creating port to ensure tcu->port
+ * is ready for any immediate incoming bytes.
+ */
+ tcu->rx = mbox_request_channel_byname(&tcu->rx_client, "rx");
+ if (IS_ERR(tcu->rx)) {
+ err = PTR_ERR(tcu->rx);
+ dev_err(&pdev->dev, "failed to get rx mailbox: %d\n", err);
+ goto remove_uart_port;
+ }
+
platform_set_drvdata(pdev, tcu);
#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
register_console(&tcu->console);
@@ -253,10 +257,10 @@ static int tegra_tcu_probe(struct platform_device *pdev)
return 0;
+remove_uart_port:
+ uart_remove_one_port(&tcu->driver, &tcu->port);
unregister_uart:
uart_unregister_driver(&tcu->driver);
-free_rx:
- mbox_free_channel(tcu->rx);
free_tx:
mbox_free_channel(tcu->tx);
@@ -270,9 +274,9 @@ static int tegra_tcu_remove(struct platform_device *pdev)
#if IS_ENABLED(CONFIG_SERIAL_TEGRA_TCU_CONSOLE)
unregister_console(&tcu->console);
#endif
+ mbox_free_channel(tcu->rx);
uart_remove_one_port(&tcu->driver, &tcu->port);
uart_unregister_driver(&tcu->driver);
- mbox_free_channel(tcu->rx);
mbox_free_channel(tcu->tx);
return 0;
--
2.30.1
