Dauren

pmdown_time=-1

pmdown_time=500

I want to clarify the essence of the problem. If the audio subsystem is turned off, the output potential is zero potential. In working condition, a voltage of about 2 volts is set at the output of the audio subsystem, which corresponds to a zero level of the output audio signal. If you install /sys/devices/platform/soc/1c22c00.codec/cdc/pmdown_time a value of -1, then after the playback of the file is finished, the output voltage is stored corresponding to the zero level of the output audio signal. But when playing a new file, the audio subsystem is completely reset. First, the zero potential is set at the output. And then the voltage of 2 volts is restored, corresponding to the zero level of the output audio signal. The duration of such an impulse is short, but a click is clearly audible on the speakers.

I try this way echo -1> /sys/devices/platform/soc/1c22c00.codec/cdc/pmdown_time It works. But when the playback is initialized, there is a reset and restoration of voltage at the processor's audio output. We saw this on an oscilloscope.

I mean internal DAC

Good day, We use NanoPi Neo Core in voice information systems. We found a problem with the implementation of Dynamic Audio Power Management for Portable Devices in H3. Our program plays voice files using the standard call of the operating system - "aplay". Before starting the reproduction of each file the voltage is discharged and restored at the output of the DAC. This leads to a loud click on the output of the audio system. Setting pmdown_time = -1 does not save the situation. Can you help in solving this problem? P.S. This problem appeared in version 4 of the kernel.