Re: [PATCH] ASoC: rsnd: Fix probe failure on HiHope boards due to endpoint parsing

[Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>]

Hi Prabhakar,

On Thu, Oct 10, 2024 at 4:15 PM Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> On the HiHope boards, we have a single port with a single endpoint defined
> as below:
> ....
>         rsnd_port: port {
>                 rsnd_endpoint: endpoint {
>                         remote-endpoint = <&dw_hdmi0_snd_in>;
>
>                         dai-format = "i2s";
>                         bitclock-master = <&rsnd_endpoint>;
>                         frame-master = <&rsnd_endpoint>;
>
>                         playback = <&ssi2>;
>                 };
>         };
> ....
>
> With commit 547b02f74e4a ("ASoC: rsnd: enable multi Component support for
> Audio Graph Card/Card2"), support for multiple ports was added. This caused
> probe failures on HiHope boards, as the endpoint could not be retrieved due
> to incorrect device node pointers being used.
>
> This patch fixes the issue by updating the `rsnd_dai_of_node()` and
> `rsnd_dai_probe()` functions to use the correct device node pointers based
> on the port names ('port' or 'ports'). It ensures that the endpoint is
> properly parsed for both single and multi-port configurations, restoring
> compatibility with HiHope boards.
>
> Fixes: 547b02f74e4a ("ASoC: rsnd: enable multi Component support for Audio Graph Card/Card2")
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Thanks for your patch!

> --- a/sound/soc/sh/rcar/core.c
> +++ b/sound/soc/sh/rcar/core.c
> @@ -1281,7 +1281,9 @@ static int rsnd_dai_of_node(struct rsnd_priv *priv, int *is_graph)
>                 if (!of_node_name_eq(ports, "ports") &&
>                     !of_node_name_eq(ports, "port"))
>                         continue;
> -               priv->component_dais[i] = of_graph_get_endpoint_count(ports);
> +               priv->component_dais[i] =
> +                       of_graph_get_endpoint_count(of_node_name_eq(ports, "ports") ?
> +                                                   ports : np);

As of_node_name_eq() is not inline or __pure, of_node_name_eq(ports,
"ports") will be called twice. So it may make sense to add a helper,
combining the selection with the validation above:

    const struct device_node *pick_endpoint_node_for_ports(const
struct device_node *np,
                const struct device_node *e_ports, const struct
device_node *e_port)
    {
            if (of_node_name_eq(ports, "ports"))
                    return e_ports;
            if (of_node_name_eq(ports, "port"))
                    return e_port;
            return NULL;
    }

>                 nr += priv->component_dais[i];
>                 i++;
>                 if (i >= RSND_MAX_COMPONENT) {
> @@ -1493,7 +1495,8 @@ static int rsnd_dai_probe(struct rsnd_priv *priv)
>                         if (!of_node_name_eq(ports, "ports") &&
>                             !of_node_name_eq(ports, "port"))
>                                 continue;
> -                       for_each_endpoint_of_node(ports, dai_np) {
> +                       for_each_endpoint_of_node(of_node_name_eq(ports, "ports") ?
> +                                                 ports : np, dai_np) {

Likewise.

>                                 __rsnd_dai_probe(priv, dai_np, dai_np, 0, dai_i);
>                                 if (!rsnd_is_gen1(priv) && !rsnd_is_gen2(priv)) {
>                                         rdai = rsnd_rdai_get(priv, dai_i);

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds