[alsa-devel] [PATCH 7/8] ASoC: Intel: add kcontrol to set parameter to sound effect module waves

[Lu, Han]

> -----Original Message-----
> From: Mark Brown [mailto:broonie at kernel.org]
> Sent: Friday, March 6, 2015 7:35 PM
> To: Lu, Han
> Cc: alsa-devel at alsa-project.org; Girdwood, Liam R
> Subject: Re: [PATCH 7/8] ASoC: Intel: add kcontrol to set parameter to sound
> effect module waves
> 
> On Mon, Mar 02, 2015 at 03:36:17PM +0800, han.lu at intel.com wrote:
> 
> > +static int hsw_waves_param_get(struct snd_kcontrol *kcontrol,
> > +				struct snd_ctl_elem_value *ucontrol) {
> > +	/* keep an empty function here to match alsa-lib calling */
> > +	return 0;
> > +}
> 
> No, if it's valid to omit this we should be able to remove the function
> - but I'd really expect to always be able to read the current state of any
> control.  Applications should be able to do that and then write the value back
> without changing anything.  Either we should actually read things back or this
> should return an error (which is presumably what the core does if the
> function is missing).

[Han Lu] OK. I made patch v2 against current code, and remove unnecessary logs. For the read back kcontrol, I do not modify patch 7/8 but add actual read back code on patch 8/8, (merge patch 7 and 8 may make the patch too long and unclear?) please review. Thanks.