DivByZero in I2S PDM Mode (IDFGH-7261)

[IgorTrud]

Environment

• Development Kit: [LILIGO-Watch V3]
• Module or chip used: [ESP32]
• IDF version ESP-IDF v5.0-dev-2586-ga82e6e63d9
• Build System: [idf.py]
• Compiler version [xtensa-esp32-elf-gcc (crosstool-NG esp-2021r2-patch3) 8.4.0]
• Operating System: [Linux]
• Using an IDE?: [No]
• Power Supply: [USB+Battery]

Problem Description

i2s_set_pdm_rx_down_sample have a bug in clock calculations

int i2s_num = 0; // i2s port number
i2s_config_t i2s_config = {
.mode = I2S_MODE_MASTER | I2S_MODE_PDM | I2S_MODE_RX,
.sample_rate = 16000,
.bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
.channel_format = I2S_CHANNEL_FMT_ONLY_RIGHT,
.communication_format = I2S_COMM_FORMAT_STAND_I2S,
.dma_desc_num = 8,
.dma_frame_num = 512, //was: 1024
.use_apll = false,
.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1 // Interrupt level 1, default 0
};

i2s_pin_config_t pin_config = {
.bck_io_num = I2S_PIN_NO_CHANGE,
.ws_io_num = 0,
.data_out_num = I2S_PIN_NO_CHANGE,
.data_in_num = 2
};

i2s_driver_install(i2s_num, &i2s_config, 0, NULL); //install and start i2s driver
i2s_set_pin(i2s_num, &pin_config);
i2s_set_clk(I2S_NUM_0, 16000, I2S_BITS_PER_SAMPLE_16BIT, I2S_CHANNEL_MONO);

i2s_set_pdm_rx_down_sample(0,I2S_PDM_DSR_16S); <---- FAILS HERE !!

---

(2871) I2S: DMA Malloc info, datalen=blocksize=1024, dma_desc_num=8
I (2872) I2S: I2S0, MCLK output by GPIO0
Guru Meditation Error: Core 0 panic'ed (IntegerDivideByZero). Exception was unhandled.

Core 0 register dump:
PC : 0x400fe212 PS : 0x00060830 A0 : 0x800fe3e9 A1 : 0x3ffbd120
0x400fe212: i2s_calculate_pdm_rx_clock at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:705

A2 : 0x00000000 A3 : 0x3ffbd180 A4 : 0x00060820 A5 : 0x3fffd70a
A6 : 0x7ff00000 A7 : 0x7fcc5f0a A8 : 0x00000000 A9 : 0x3ffd73c4
A10 : 0x00000000 A11 : 0x00060823 A12 : 0x00000000 A13 : 0x3ffbd000
A14 : 0x00000034 A15 : 0x3ffbd000 SAR : 0x0000001b EXCCAUSE: 0x00000006
EXCVADDR: 0x00000000 LBEG : 0x400029ac LEND : 0x400029cb LCOUNT : 0x00000000

Backtrace:0x400fe20f:0x3ffbd1200x400fe3e6:0x3ffbd150 0x400fe460:0x3ffbd180 0x400ff444:0x3ffbd1b0 0x400ff61a:0x3ffbd1e0 0x400da212:0x3ffbd210 0x400d7d82:0x3ffbd2d0 0x4016a947:0x3ffbd350 0x40094641:0x3ffbd370
0x400fe20f: i2s_calculate_pdm_rx_clock at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:703 (discriminator 1)
0x400fe3e6: i2s_calculate_clock at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:768
0x400fe460: i2s_set_clock_legacy at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:1007
0x400ff444: i2s_set_clk at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:1058 (discriminator 4)
0x400ff61a: i2s_set_pdm_rx_down_sample at /home/igor/Projects/esp/esp-idf/components/driver/i2s.c:1136 (discriminator 2)
0x400da212: audio_start at /home/igor/Projects/esp/espwatch/build/../main/audio.c:333
0x400d7d82: app_main at /home/igor/Projects/esp/espwatch/build/../main/espwatch.c:172

[Alvin1Zhang]

Thanks for reporting, fix on master branch is available at 94d7ae0, and we will also backport the fix to release/4.4, thanks.