Re: [alsa-devel] [RFC/RFT PATCH] ASoC: topology: Improve backwards compatibility with v4 topology files

[Guenter Roeck]

On Fri, May 25, 2018 at 6:42 AM Shreyas NC <shreyas.nc@xxxxxxxxx> wrote:

> > > > +struct skl_dfw_v4_pipe {
> > > > +     u8 pipe_id;
> > > > +     u8 pipe_priority;
> > > > +     u16 conn_type:4;
> > > > +     u16 rsvd:4;
> > > > +     u16 memory_pages:8;
> > > > +} __packed;
> > > > +
> > > > +struct skl_dfw_v4_module {
> > > > +     char uuid[SKL_UUID_STR_SZ];
> > > > +

> Any reason to not have this as u8?
> commit 09305da97c7808b900985526aa9198233f32fb37 had changed this to u8..

No reason. I'll fix it.

> <snip>

> > > > +
> > > > +     mconfig->params_fixup = dfw->params_fixup;
> > > > +     mconfig->converter = dfw->converter;
> > > > +     mconfig->m_type = dfw->module_type;
> > > > +     mconfig->vbus_id = dfw->vbus_id;
> > > > +     mconfig->module->resources[0].is_pages = dfw->mem_pages;
> > > > +
> > > > +     ret = skl_tplg_add_pipe_v4(dev, mconfig, skl, &dfw->pipe);
> > > > +     if (ret)
> > > > +             return ret;
> > > > +
> > > > +     mconfig->dev_type = dfw->dev_type;
> > > > +     mconfig->hw_conn_type = dfw->hw_conn_type;
> > > > +     mconfig->time_slot = dfw->time_slot;
> > > > +     mconfig->formats_config.caps_size = dfw->caps.caps_size;
> >
> > > chromeos-3.18 has this:
> > >       if (dfw_config->is_loadable)
> > >           memcpy(mconfig->guid, dfw_config->uuid,
> > >                       ARRAY_SIZE(dfw_config->uuid));
> >
> > > Is this needed here?
> >
> >
> > Direct memcpy doesn't work anymore since the uuid format is different.
The
> > above is replaced
> > with (unconditional)
> >
> >          ret = guid_parse(dfw->uuid, (guid_t *)mconfig->guid);
> >          if (ret)
> >                  return ret;
> >
> > at the beginning of skl_tplg_get_pvt_data_v4(). The new code, as far as
I
> > can see, loads
> > the uuid unconditionally if it finds SND_SOC_TPLG_TUPLE_TYPE_UUID. I
wanted
> > to
> > be on the safe side and decided to do the same.
> >

> In the new code, still does a memcpy(). So, I am not sure if I understand
> why memcpy() does not work.

>          if (uuid_tkn->token == SKL_TKN_UUID) {
>                  memcpy(guid, &uuid_tkn->uuid, 16);
>                  return 0;
>          }

The new (v5) configuration files provide the uuid as binary and no longer
as text.

Guenter