[alsa-devel] [PATCH 1/2] ASoC: atmel-classd: add the Audio Class D Amplifier code

[Wu, Songjun]

On 9/8/2015 20:23, Mark Brown wrote:
> On Tue, Sep 08, 2015 at 05:36:01PM +0800, Wu, Songjun wrote:
>> On 9/8/2015 00:23, Mark Brown wrote:
>
>>> OK, so that's not actually what the code was doing - it had separate
>>> enums for bass, mid and treble.  If you make this a single enum with all
>>> the above options in it that seems like the best way of handling things.
>
>> A single enum seems not very friendly to user, there are tree EQs, bass,
>> medium and treble.
>> So I create tree enum controls to control three EQs.
>> The 'get' function is replaced by 'classd_get_eq_enum', if user operates one
>> of the tree EQ controls, the other two EQs will show 0 dB.
>
> If you want to have three controls you need to write code so that the
> user can only change one of them from 0dB at once, returning an error
> otherwise.  That was why it looked like they were three separate
> controls.
>
If user operates two or tree controls at the same time, for my 
understanding, these operations are serial actually in kernel, not 
parallel, and the last operation will be effective. I only write the 
function 'classd_get_eq_enum' to get the enumeration value, if user 
changes one of controls, the other controls will get 0dB. Is my 
understanding correct?