Commit af9a1f61 authored by Mikko Perttunen's avatar Mikko Perttunen Committed by Greg Kroah-Hartman
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serial: tegra-tcu: Reorder channel initialization 



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: 2d908b38 ("serial: Add Tegra Combined UART driver")
Signed-off-by: default avatarMikko Perttunen <mperttunen@nvidia.com>
Link: https://lore.kernel.org/r/20210609155655.3567545-1-mperttunen@nvidia.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 08a84410

drivers/tty/serial/tegra-tcu.c

+15 −11
Original line number Diff line number Diff line
@@ -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;