IMX8MP - No audio during playback with SOF sound card

[aporter28]

Hi,

I am trying to run playback using the SOF sound card on the IMX8M Plus EVK, but I am not able to hear any audio from the headphone jack.

Here are the steps I am using to run the playback:

1. Boot the device and interrupt to enter uboot
2. Use "editenv fdtfile" and change the device tree name to "imx8mp-evk-sof-wm8960.dtb"
3. Continue the boot
4. Run "aplay -l" to obtain SOF sound card ID
5. Run the following commands to initiate playback:
   1. amixer -c [sof_card_id] cset name="Left Output Mixer PCM Playback Switch" on
   2. amixer -c [sof_card_id] cset name="Right Output Mixer PCM Playback Switch" on
   3. aplay -Dhw:[sof_card_id],0 [path_to_wav_file]

The wav file used in this case is 32 bit, 48Khz stereo. I see no error when running the playback command.

I have also tried playing the same wav file using the default device tree and the wm8960 sound card, and I am able to hear the output.

Please let me know what I can do to solve this issue.

[dbaluta · Accepted solution]

Hello @aporter28 ,

On my setup the control you want to modify is named 'Headphone'.

Assuming SOF card number is 0 please try this.

amixer -c 0 sset Headphone 80%

Also you can use the alsamixer TUI and modify the Headphone control


Can you share with us what project are you working on with the Sound Open Firmware? 

[aporter28]

That worked great, thanks! I am currently just exploring the capabilities of SOF on NXP boards.

[Zhiming_Liu]

Hi @aporter28 

Did you refer this guide?

SOF User Guide on NXP i.MX8 platforms — SOF Project 2.11.0 documentation

Best Regards,
Zhiming