Re: [PATCH v2 2/3] serial: mtk: guard clk ops on clk.dev

Le ven. 31 juil. 2026 à 21:39, David Lechner <[email protected]> a écrit :
>
> From: Suhrid Subramaniam <[email protected]>
>
> Check that priv->clk has been populated before trying to use it in the
> MediaTek serial driver.
>
> The clock is optional and may not be populated in all cases (in which
> case it is expected that there was a fixed clock rate provided.)
>
> Fixes: 3b17f2e2c2a9 ("serial: mtk: add support for using dynamic baud clock souce")
> Signed-off-by: Suhrid Subramaniam <[email protected]>
> Signed-off-by: David Lechner <[email protected]>
> ---
>  drivers/serial/serial_mtk.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c
> index 28e87f485a2..fff2f639cf6 100644
> --- a/drivers/serial/serial_mtk.c
> +++ b/drivers/serial/serial_mtk.c
> @@ -215,9 +215,13 @@ static int mtk_serial_setbrg(struct udevice *dev, int baudrate)
>         struct mtk_serial_priv *priv = dev_get_priv(dev);
>         ulong clk_rate;
>
> -       clk_rate = clk_get_rate(&priv->clk);
> -       if (IS_ERR_VALUE(clk_rate) || clk_rate == 0)
> +       if (priv->clk.dev) {

What about using  clk_valid() ?

> +               clk_rate = clk_get_rate(&priv->clk);
> +               if (IS_ERR_VALUE(clk_rate) || clk_rate == 0)
> +                       return -EINVAL;
> +       } else {
>                 clk_rate = priv->fixed_clk_rate;
> +       }
>
>         _mtk_serial_setbrg(priv, baudrate, clk_rate);
>
> @@ -255,7 +259,8 @@ static int mtk_serial_probe(struct udevice *dev)
>         writel(UART_MCRVAL, &priv->regs->mcr);
>         writel(UART_FCRVAL, &priv->regs->fcr);
>
> -       clk_enable(&priv->clk);
> +       if (priv->clk.dev)
> +               clk_enable(&priv->clk);

Same here,  clk_valid()?
Also, this change is purely cosmetic, since clk_enable() already call
clk_valid()

>         if (priv->clk_bus.dev)
>                 clk_enable(&priv->clk_bus);
>
>
> --
> 2.43.0
>