-----Original Message----- From: Mark Brown [mailto:broonie@kernel.org] Sent: Friday, March 6, 2015 7:35 PM To: Lu, Han Cc: alsa-devel@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@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.