[Hardy LPIA LUM]: RealTek hda-intel volume remapping for non-linear volume scales

[Colin Ian King]

Hi Tim,

On Tue, 2009-04-21 at 09:33 -0600, Tim Gardner wrote: 
> Colin Ian King wrote:
> > LP#249233 - sound volume too low.
> > 
> > for Hardy LPIA LUM.
> > 
[ Text deleted ]

> Is this really doing what you expect?
> 
>  static int slave_get_val(struct link_slave *slave,
>                          struct snd_ctl_elem_value *ucontrol)
>  {
> @@ -305,8 +360,15 @@ static int master_put(struct snd_kcontrol *kcontrol,
>                 master->val = old_val;
>                 uval->id = slave->slave.id;
>                 slave_get_val(slave, uval);
> -               master->val = ucontrol->value.integer.value[0];
> +
> +               /* Put to slaves a remapped volume */
> +               master->val = vol_remap(master->info.min_val,
> +                                       master->info.max_val,
> +                                       ucontrol->value.integer.value[0]);
>                 slave_put_val(slave, uval);
> +               /* And actually save the original unremapped volume
> +                  for master_get() */
> +               master->val = ucontrol->value.integer.value[0];
>         }
>         kfree(uval);
>         return 1;
> 
> I looks like master-val is simply set twice (unless there are side
> effects happening in slave_put_val()).

It's good to know your eye is keen... 

The fact is that slave_put_val() requires a master->val to be set for
the volume to be set correctly (this case a remapped version). However
master->val can be interrogated later for the master volume setting, and
we need to return the expected value and not the remapped value else we
get ALSA confused. Without a major rewrite of slave_put_xval() I cannot
see around this.

Colin

> 
> rtg
> 
> -- 
> Tim Gardner tim.gardner at canonical.com
> 
-- 
Colin King   <colin.king at canonical.com>
"Me transmitte sursum, caledoni"