tinycap Captured 0 frames on i.mx8mq android 13

[peterwu2]

we use a hdmi-csi convertor LT6911.
LT6911 play I2S master. we connect to SAI3 of i.mx8mq.

hdmi plug to pc and playing youtube.

we can measure I2S signal. ( RXD0 , RXC, RXFS ) .   

LT6911 have external osc, so the MCLK is not connect.

RXC = 48kHz (RXFS) x 32 x2 = 3.072MHz 

RXD0RXCRXFS

the dts config.

	lt6911c_1_codec: lt6911c_1-codec {
		compatible = "dummy-codec";
		#sound-dai-cells = <0>;
	};

	sound-lt6911c_1 {
		compatible = "simple-audio-card";
		simple-audio-card,name = "lt6911c_1-audio";
		simple-audio-card,format = "i2s";
		simple-audio-card,frame-master = <&lt6911c_1_codec_dai>;
		simple-audio-card,bitclock-master = <&lt6911c_1_codec_dai>;

		lt6911c_1_codec_dai: simple-audio-card,cpu {
			sound-dai = <&sai3>;
			dai-tdm-slot-num = <2>;
			dai-tdm-slot-width = <32>;
		};

		simple-audio-card,codec {
			sound-dai = <&lt6911c_1_codec 0>;
		};
	};


&sai3 {
	#sound-dai-cells = <0>;
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_sai3>;
	assigned-clocks = <&clk IMX8MQ_CLK_SAI3>;
	assigned-clock-parents = <&clk IMX8MQ_AUDIO_PLL1_OUT>;
	assigned-clock-rates = <24576000>;
	clock-names = "bus", "mclk0", "mclk1", "mclk2", "mclk3", "pll8k", "pll11k";
	clocks = <&clk IMX8MQ_CLK_SAI3_IPG>, <&clk IMX8MQ_CLK_DUMMY>,
		<&clk IMX8MQ_CLK_SAI3_ROOT>, <&clk IMX8MQ_CLK_DUMMY>,
		<&clk IMX8MQ_CLK_DUMMY>, <&clk IMX8MQ_AUDIO_PLL1_OUT>,
		<&clk IMX8MQ_AUDIO_PLL2_OUT>;
	fsl,sai-asynchronous;
	status = "okay";
};

	pinctrl_sai3: sai3grp {
		fsl,pins = <			
			MX8MQ_IOMUXC_SAI3_RXC_SAI3_RX_BCLK			0xd6
			MX8MQ_IOMUXC_SAI3_RXFS_SAI3_RX_SYNC			0xd6
			MX8MQ_IOMUXC_SAI3_RXD_SAI3_RX_DATA0			0xd6
		>;
	};

sound cards ( there is pcmC0D0c )

chimera:/data # ls /dev/snd -al
total 0
drwxr-xr-x  2 root   root       220 1970-01-01 00:00 .
drwxr-xr-x 24 root   root      1960 1970-01-01 00:00 ..
crw-rw----  1 system audio 116,   3 1970-01-01 00:00 controlC0
crw-rw----  1 system audio 116,   6 1970-01-01 00:00 controlC1
crw-rw----  1 system audio 116,   9 1970-01-01 00:00 controlC2
crw-rw----  1 system audio 116,   2 1970-01-01 00:00 pcmC0D0c
crw-rw----  1 system audio 116,   5 1970-01-01 00:00 pcmC1D0c
crw-rw----  1 system audio 116,   4 1970-01-01 00:00 pcmC1D0p
crw-rw----  1 system audio 116,   8 1970-01-01 00:00 pcmC2D0c
crw-rw----  1 system audio 116,   7 1970-01-01 00:00 pcmC2D0p
crw-rw----  1 system audio 116,  33 1970-01-01 00:00 timer

chimera:/data # cat /proc/asound/cards
 0 [lt6911c1audio  ]: simple-card - lt6911c_1-audio
                      lt6911c_1-audio
 1 [btscoaudio     ]: simple-card - bt-sco-audio
                      bt-sco-audio
 2 [wm8904audio    ]: wm8904-audio - wm8904-audio
                      wm8904-audio

we try to capture wav on android 13, it Captured 0 frames.  the wav file is empty

# tinycap test.wav -D 0
Capturing sample: 2 ch, 44100 hz, 16 bit
Captured 0 frames

the same configuration on android 11.  capture wav is success.

why it fail on android 13, Any suggestion ? 

[peterwu2 · Accepted solution]

It work.  my typing error in dts