Re: [PATCH] serial: fsl_lpuart: Remove the alias node dependence

From: Greg KH
Date: Wed Jan 11 2017 - 02:24:40 EST


On Wed, Dec 14, 2016 at 04:33:32PM +0800, Yuan Yao wrote:
> From: Yuan Yao <yao.yuan@xxxxxxx>
>
> Numbering the ttyLPn space should not depend on the generic name
> "serial<n>".
>
> If don't add the alias node like:"serial0 = &lpuart0;", then lpuart
> will probe failed:
> [ 0.773410] fsl-lpuart 2950000.serial: failed to get alias id, errno -19
>
> So remove the alias node dependence, and add the support for allocate the
> line port automatically.
>
> Signed-off-by: Yuan Yao <yao.yuan@xxxxxxx>
> ---
> drivers/tty/serial/fsl_lpuart.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
> index a1c6519..c6d639f 100644
> --- a/drivers/tty/serial/fsl_lpuart.c
> +++ b/drivers/tty/serial/fsl_lpuart.c
> @@ -231,6 +231,8 @@
> #define DEV_NAME "ttyLP"
> #define UART_NR 6
>
> +static DECLARE_BITMAP(linemap, UART_NR);

Why a bitmap?

> +
> struct lpuart_port {
> struct uart_port port;
> struct clk *clk;
> @@ -1963,9 +1965,13 @@ static int lpuart_probe(struct platform_device *pdev)
>
> ret = of_alias_get_id(np, "serial");
> if (ret < 0) {
> - dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
> - return ret;
> + ret = find_first_zero_bit(linemap, UART_NR);
> + if (ret >= UART_NR) {
> + dev_err(&pdev->dev, "port line is full, add device failed\n");
> + return ret;
> + }

Does this really remove the alias dependancy?

Please use an idr or ida for this instead of a bitmap.

thanks,

greg k-h