STM32MP135 + SGTL5000: arecord fails with `pcm_read: Input/output error` while aplay works

[Midhul_Pk]

Hi,

I am working on STM32MP135 with SGTL5000 codec using ALSA/ASoC.

Playback is working correctly:

aplay -D default /home/audio/test_audio.wav

But audio capture is failing with Input/output error:

root@stm32mp135-comtrol:~# arecord -D hw:0,1 -f S16_LE -r 48000 -c 2 test.wav
Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
arecord: pcm_read:2272: read error: Input/output error

Current status:

• Playback works correctly
• Codec detected properly
• I2C communication seems OK during playback
• Capture stream fails immediately after start

root@stm32mp135-comtrol:~# arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: STM32SGTL5000 [STM32-SGTL5000], device 1: 4400a024.audio-controller-sgtl5000 sgtl5000-1 [4400a024.audio-controller-sgtl5000 sgtl5000-1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Device tree configuration is attached below.

Questions:

1. What usually causes pcm_read: Input/output error in ALSA capture?
2. Could this be related to SAI RX configuration?
3. Is there any missing SGTL5000 mixer/control configuration required for recording?
4. Does hw:0,1 indicate incorrect capture routing?

I checked:

• LRCLK = 48kHz
• BCLK = 1.536MHz
• MCLK present
• Playback path working

But capture still fails.

Device Tree :-  

Pins :- 

	
	sai1_pins_a: sai1-0 {
		pins {
		    pinmux = <STM32_PINMUX('A', 4, AF12)>, /* SAI1_SCK_A */
		             <STM32_PINMUX('A', 0, AF6)>, /* SAI1_SD_B */
		             <STM32_PINMUX('A', 5, AF6)>, /* SAI1_SD_A */
		             <STM32_PINMUX('F', 11, AF6)>, /* SAI1_FS_A */
		             <STM32_PINMUX('D', 13, AF6)>; /* SAI1_MCKA */
		    slew-rate = <0>;
		    drive-push-pull;
		    bias-disable;
		};
	    };

	    sai1_sleep_pins_a: sai1-sleep-0 {
		pins {
		    pinmux = <STM32_PINMUX('A', 4, ANALOG)>, /* SAI1_SCK_A */
		             <STM32_PINMUX('A', 0, ANALOG)>, /* SAI1_SD_B */
		             <STM32_PINMUX('A', 5, ANALOG)>, /* SAI1_SD_A */
		             <STM32_PINMUX('F', 11, ANALOG)>, /* SAI1_FS_A */
		             <STM32_PINMUX('D', 13, ANALOG)>; /* SAI1_MCKA */
		};
	    };

Sound :-

	sound {
		compatible = "simple-audio-card";
		simple-audio-card,name = "STM32-SGTL5000";

		simple-audio-card,widgets =
			"Microphone", "Mic Jack",
			"Headphone", "Headphone Jack",
			"Line", "Line In",
			"Line", "Line Out";

		simple-audio-card,routing =
			"Headphone Jack", "HP_OUT",
			"Line Out", "LINE_OUT",
			"Mic Jack", "MIC_IN",
			"LINE_IN", "Line In";

		/* Playback */
		simple-audio-card,dai-link@0 {
			format = "i2s";

			bitclock-master = <&cpu_tx>;
			frame-master = <&cpu_tx>;

			mclk-fs = <256>;

			cpu_tx: cpu {
				sound-dai = <&sai1a>;
			};

			codec_tx: codec {
				sound-dai = <&sgtl5000>;
			};
		};

		/* Capture */
		simple-audio-card,dai-link@1 {
			format = "i2s";

			bitclock-master = <&cpu_tx>;
			frame-master = <&cpu_tx>;

			mclk-fs = <256>;

			cpu {
				sound-dai = <&sai1b>;
			};

			codec {
				sound-dai = <&sgtl5000>;
			};
		};
	};

CODEC :-

	sgtl5000: codec@0a {
	    compatible = "fsl,sgtl5000";
	    reg = <0x0a>;
	    status = "okay";

	    #sound-dai-cells = <0>;

	    VDDA-supply = <&scmi_v3v3_sw>;
	    VDDIO-supply = <&scmi_v3v3_sw>;

	    clocks = <&sai1a>;
	    clock-names = "mclk";
	};

 SAI :-

&sai1 {
	status = "okay";

	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&sai1_pins_a>;
	pinctrl-1 = <&sai1_sleep_pins_a>;

	clock-names = "pclk", "x8k", "x11k";

	clocks = <&rcc SAI1>,
		 <&scmi_clk CK_SCMI_PLL3_Q>,
		 <&scmi_clk CK_SCMI_PLL3_R>;

	assigned-clocks = <&rcc SAI1_K>;
	assigned-clock-parents = <&scmi_clk CK_SCMI_PLL3_Q>;
	assigned-clock-rates = <12288000>;

	sai1a: audio-controller@4400a004 {
		compatible = "st,stm32-sai-sub-a";
		reg = <0x4 0x20>;

		#sound-dai-cells = <0>;

		clocks = <&rcc SAI1_K>;
		clock-names = "sai_ck";

		#clock-cells = <0>;
		clock-output-names = "sai1a_mclk";

		st,sai-mclk-output;

		dmas = <&dmamux1 87 0x400 0x01>;
		dma-names = "tx";

		status = "okay";
	};

	sai1b: audio-controller@4400a024 {
		compatible = "st,stm32-sai-sub-b";
		reg = <0x24 0x20>;

		#sound-dai-cells = <0>;

		clocks = <&rcc SAI1_K>;
		clock-names = "sai_ck";

		st,sync = <&sai1a 1>;

		dmas = <&dmamux1 88 0x400 0x01>;
		dma-names = "rx";

		status = "okay";
	};
};

 Any help would be appreciated. 

[Gregory PLANCHON]

Hi @Midhul_Pk ,

Did you check out this page to run your tests?
Also, I can't say for sure that this is the root cause, but `simple-audio-card` is quite limited. It's better to use `audio-graph-card`. You can find examples on our forums on this page

Regards,

Grégory