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

["Lad, Prabhakar" <prabhakar.csengg@xxxxxxxxx>]

Hi Geert,

Thank you for the review.

On Fri, Oct 11, 2024 at 7:42 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> 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;
>     }
>
I'll drop the const maybe to reduce the diff and  have something like below:

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

and use it like below in the rsnd_dai_of_node() function:

@@ -1278,10 +1291,10 @@ static int rsnd_dai_of_node(struct rsnd_priv
*priv, int *is_graph)
         * Audio-Graph-Card
         */
        for_each_child_of_node(np, ports) {
-               if (!of_node_name_eq(ports, "ports") &&
-                   !of_node_name_eq(ports, "port"))
+               node = pick_endpoint_node_for_ports(ports, np);
+               if (!node)
                        continue;
-               priv->component_dais[i] = of_graph_get_endpoint_count(ports);
+               priv->component_dais[i] = of_graph_get_endpoint_count(node);


> >                 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.
>
Ok, now I will have to create a local variable for this loop, which
will look like something below:

@@ -1486,14 +1499,15 @@ static int rsnd_dai_probe(struct rsnd_priv *priv)
         */
        dai_i = 0;
        if (is_graph) {
+               struct device_node *dai_np_port;
                struct device_node *ports;
                struct device_node *dai_np;

                for_each_child_of_node(np, ports) {
-                       if (!of_node_name_eq(ports, "ports") &&
-                           !of_node_name_eq(ports, "port"))
+                       dai_np_port = pick_endpoint_node_for_ports(ports, np);
+                       if (!dai_np_port)
                                continue;
-                       for_each_endpoint_of_node(ports, dai_np) {
+                       for_each_endpoint_of_node(dai_np_port, dai_np) {
                                __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);

Does that sound OK?

Cheers,
Prabhakar