Re: [PATCH] ASoC: qcom: audioreach: support multichannel PCM formats

[Zhangfei Gao]

On Mon, Oct 26, 2026 at 2:19 PM Prasad Kumpatla
<prasad.kumpatla@xxxxxxxxxxxxxxxx> wrote:
>
> >   void audioreach_set_default_channel_mapping(u8 *ch_map, int num_channels)
> >   {
> > -     if (num_channels == 1) {
> > -             ch_map[0] =  PCM_CHANNEL_FL;
> > -     } else if (num_channels == 2) {
> > -             ch_map[0] =  PCM_CHANNEL_FL;
> > -             ch_map[1] =  PCM_CHANNEL_FR;
> > -     } else if (num_channels == 4) {
> > -             ch_map[0] =  PCM_CHANNEL_FL;
> > -             ch_map[1] =  PCM_CHANNEL_FR;
> > -             ch_map[2] =  PCM_CHANNEL_LS;
> > -             ch_map[3] =  PCM_CHANNEL_RS;
> > +     memset(ch_map, 0, AR_PCM_MAX_NUM_CHANNEL);
> > +
> > +     switch (num_channels) {
> > +     case 1:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             break;
> > +     case 2:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             break;
> > +     case 3:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_FC;
> > +             break;
> > +     case 4:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_LS;
> > +             ch_map[3] = PCM_CHANNEL_RS;
> > +             break;
> > +     case 5:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_FC;
> > +             ch_map[3] = PCM_CHANNEL_LS;
> > +             ch_map[4] = PCM_CHANNEL_RS;
> > +             break;
> > +     case 6:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_LFE;
> > +             ch_map[3] = PCM_CHANNEL_FC;
> > +             ch_map[4] = PCM_CHANNEL_LS;
> > +             ch_map[5] = PCM_CHANNEL_RS;
> > +             break;
> > +     case 7:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_LFE;
> > +             ch_map[3] = PCM_CHANNEL_FC;
> > +             ch_map[4] = PCM_CHANNEL_LS;
> > +             ch_map[5] = PCM_CHANNEL_RS;
> > +             ch_map[6] = PCM_CHANNEL_CS;
> > +             break;
> > +     case 8:
> > +             ch_map[0] = PCM_CHANNEL_FL;
> > +             ch_map[1] = PCM_CHANNEL_FR;
> > +             ch_map[2] = PCM_CHANNEL_LFE;
> > +             ch_map[3] = PCM_CHANNEL_FC;
> > +             ch_map[4] = PCM_CHANNEL_LS;
> > +             ch_map[5] = PCM_CHANNEL_RS;
> > +             ch_map[6] = PCM_CHANNEL_LB;
> > +             ch_map[7] = PCM_CHANNEL_RB;
> > +             break;
> >       }
> >   }
> >   EXPORT_SYMBOL_GPL(audioreach_set_default_channel_mapping);
>
> audioreach_set_default_channel_mapping() silently leaves an all-zero channel map for unsupported channel counts.
> Since this helper is exported and callers such as q6apm_dai_prepare/q6dma_hw_params/q6hdmi_hw_params() don't validate the range.
>
> would it make sense to return -EINVAL for unsupported values and have callers propagate the error?

Thanks Prasad,

Then we can directly reuse q6dsp_map_channels to make it simpler.
Will update.

Thanks