Gentle ping...
> -----Original Message-----
> From: Sherry Sun
> Sent: 2022年3月21日 19:25
> To: gregkh@xxxxxxxxxxxxxxxxxxx; jirislaby@xxxxxxxxxx; Vabhav Sharma
> <vabhav.sharma@xxxxxxx>
> Cc: linux-serial@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dl-linux-imx
> <linux-imx@xxxxxxx>
> Subject: [PATCH] tty: serial: fsl_lpuart: fix potential bug when using both
> of_alias_get_id and ida_simple_get
>
> 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>
> ---
> drivers/tty/serial/fsl_lpuart.c | 24 ++++--------------------
> 1 file changed, 4 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
> index 452a015825ba..40465d23d7ad 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 {
> @@ -2716,23 +2713,18 @@ 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)
> failed_attach_port:
> failed_irq_request:
> 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);
> }
> --
> 2.17.1
