Hello!
What does the trace show now? I appears that it is trying to turn on the I2S interface which is a good sign …
$ echo 0 | sudo tee /sys/kernel/debug/tracing/trace
$ echo 0 | sudo tee /sys/kernel/debug/tracing/events/enable
$ echo 1 | sudo tee /sys/kernel/debug/tracing/tracing_on
$ echo 1 | sudo tee /sys/kernel/debug/tracing/events/asoc/snd_soc_dapm_path/enable
$ echo 1 | sudo tee /sys/kernel/debug/tracing/events/asoc/snd_soc_dapm_widget_power/enable
$ speaker-test -D hw:tegrasndt210ref,0 -c 2 -r 48000 -F S16_LE -t sine -f 500
$ sudo cat /sys/kernel/debug/tracing/trace
The error you are seeing is a common error if the BCLK is not enabled before the I2S interface is enabled. This causes the I2S soft reset to fail and the above error message is seen. So you need to ensure that the PLL is being turned on and the BCLK is active before the I2S soft reset function is called. It could be a problem with I2S pinmux not being configured correctly and so the I2S cannot detect the BCLK. If you dump the following we can check the pinmux …
$ sudo grep dap1 /sys/kernel/debug/tegra_pinctrl_reg
The pinmux values should be something like what is seen here:
Jon