This is a note to let you know that I've just added the patch titled tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_simple_get to the 5.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tty-serial-fsl_lpuart-fix-potential-bug-when-using-b.patch and it can be found in the queue-5.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 35b48baeffe21800f0d255be592474d3bc578667 Author: Sherry Sun <sherry.sun@xxxxxxx> Date: Mon Mar 21 19:22:11 2022 +0800 tty: serial: fsl_lpuart: fix potential bug when using both of_alias_get_id and ida_simple_get [ Upstream commit f398e0aa325c61fa20903833a5b534ecb8e6e418 ] Now fsl_lpuart driver use both of_alias_get_id() and ida_simple_get() in .probe(), which has the potential bug. For example, when remove the lpuart7 alias in dts, of_alias_get_id() will return error, then call ida_simple_get() to allocate the id 0 for lpuart7, this may confilct with the lpuart4 which has alias 0. aliases { ... serial0 = &lpuart4; serial1 = &lpuart5; serial2 = &lpuart6; serial3 = &lpuart7; } So remove the ida_simple_get() in .probe(), return an error directly when calling of_alias_get_id() fails, which is consistent with other uart drivers behavior. Fixes: 3bc3206e1c0f ("serial: fsl_lpuart: Remove the alias node dependence") Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx> Link: https://lore.kernel.org/r/20220321112211.8895-1-sherry.sun@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index be12fee94db5..2cb89491dd09 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -239,8 +239,6 @@ /* IMX lpuart has four extra unused regs located at the beginning */ #define IMX_REG_OFF 0x10 -static DEFINE_IDA(fsl_lpuart_ida); - enum lpuart_type { VF610_LPUART, LS1021A_LPUART, @@ -276,7 +274,6 @@ struct lpuart_port { int rx_dma_rng_buf_len; unsigned int dma_tx_nents; wait_queue_head_t dma_wait; - bool id_allocated; }; struct lpuart_soc_data { @@ -2717,23 +2714,18 @@ static int lpuart_probe(struct platform_device *pdev) ret = of_alias_get_id(np, "serial"); if (ret < 0) { - ret = ida_simple_get(&fsl_lpuart_ida, 0, UART_NR, GFP_KERNEL); - if (ret < 0) { - dev_err(&pdev->dev, "port line is full, add device failed\n"); - return ret; - } - sport->id_allocated = true; + dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); + return ret; } if (ret >= ARRAY_SIZE(lpuart_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", ret); - ret = -EINVAL; - goto failed_out_of_range; + return -EINVAL; } sport->port.line = ret; ret = lpuart_enable_clks(sport); if (ret) - goto failed_clock_enable; + return ret; sport->port.uartclk = lpuart_get_baud_clk_rate(sport); lpuart_ports[sport->port.line] = sport; @@ -2781,10 +2773,6 @@ static int lpuart_probe(struct platform_device *pdev) uart_remove_one_port(&lpuart_reg, &sport->port); failed_attach_port: lpuart_disable_clks(sport); -failed_clock_enable: -failed_out_of_range: - if (sport->id_allocated) - ida_simple_remove(&fsl_lpuart_ida, sport->port.line); return ret; } @@ -2794,9 +2782,6 @@ static int lpuart_remove(struct platform_device *pdev) uart_remove_one_port(&lpuart_reg, &sport->port); - if (sport->id_allocated) - ida_simple_remove(&fsl_lpuart_ida, sport->port.line); - lpuart_disable_clks(sport); if (sport->dma_tx_chan) @@ -2926,7 +2911,6 @@ static int __init lpuart_serial_init(void) static void __exit lpuart_serial_exit(void) { - ida_destroy(&fsl_lpuart_ida); platform_driver_unregister(&lpuart_driver); uart_unregister_driver(&lpuart_reg); }