On 2/18/21 3:44 AM, Jaroslav Kysela wrote:
Dne 18. 02. 21 v 10:12 shumingf@xxxxxxxxxxx napsal(a):
+ SND_SOC_DAPM_SWITCH("DAC L", SND_SOC_NOPM, 0, 0, &rt1316_sto_dac_l),
+ SND_SOC_DAPM_SWITCH("DAC R", SND_SOC_NOPM, 0, 0, &rt1316_sto_dac_r),
Truly, I don't understand the reason to have a separate L/R switch when we can
map this functionality to one stereo (multichannel) control.
It's an issue for all ASoC drivers. We should consider to be more strict for
the new ones.
At the same time we have to recognize that the L/R notion only makes
sense at the input to the amplifier. The amplifier may recombine
channels to deal with orientation/posture or simply select a specific
input, and drive different speakers (e.g. tweeter/woofer). Dac L and R
are often an abuse of language when the system have multi-way speakers.
Exhibit A for this is the TigerLake device with 2 RT1316 and 4 speakers.
L/R don't make sense to describe amplifier outputs and speaker position.
There's also a difficult balance to be found between exposing all the
capabilities of the device, and making integration and userspace
simpler. I2C/IS2 and SoundWire devices tend to expose more controls than
HDaudio ones, and that was driven by a desire to optimize as much as
possible. Some devices are designed with limited number of controls,
others provide hooks to tweak everything in the system by exposing
literally have thousands of controls. I don't think we should pick and
choose which controls we want to expose, that's the codec vendor's job
IMHO (or the device class definition when standard and applicable)