crash/reboot in writing to SPI?!

[stapelberg]

Sometimes (haven’t figured out when or why exactly), my M5ez-based UI crashes/reboots with the following backtrace:

Backtrace: 0x4008ce58:0x3ffbe170 0x4008d089:0x3ffbe190 0x400ee51b:0x3ffbe1b0 0x40085161:0x3ffbe1d0 0x400e2329:0x3ffce600 0x400e2535:0x3ffce620 0x400d710e:0x3ffce650 0x400d1886:0x3ffce670 0x400d199e:0x3ffce6a0 0x401693db:0x3ffce6c0 0x400e871e:0x3ffce6e0 0x400d1612:0x3ffce720 0x4008956d:0x3ffce740

GDB says:

(gdb) l *0x4008ce58
0x4008ce58 is in invoke_abort (/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c:155).
(gdb) l *0x4008d089
0x4008d089 is in abort (/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c:170).
(gdb) l *0x400ee51b
0x400ee51b is in task_wdt_isr (/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/task_wdt.c:174).
(gdb) l *0x40085161
0x40085161 is at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/xtensa_vectors.S:1154.
(gdb) l *0x400e2329
0x400e2329 is in writeBlock(unsigned short, unsigned int) (/home/michael/Arduino/libraries/M5Stack/src/utility/In_eSPI.cpp:5316).
5311	  if (repeat > 31) // Revert legacy toggle buffer change
5312	  {
5313	    WRITE_PERI_REG(SPI_MOSI_DLEN_REG(SPI_PORT), 511);
5314	    while(repeat>31)
5315	    {
5316	      while (READ_PERI_REG(SPI_CMD_REG(SPI_PORT))&SPI_USR);
5317	      WRITE_PERI_REG(SPI_W0_REG(SPI_PORT), color32);
5318	      WRITE_PERI_REG(SPI_W1_REG(SPI_PORT), color32);
5319	      WRITE_PERI_REG(SPI_W2_REG(SPI_PORT), color32);
5320	      WRITE_PERI_REG(SPI_W3_REG(SPI_PORT), color32);
(gdb) l *0x400e2535
0x400e2535 is in TFT_eSPI::fillRect(int, int, int, int, unsigned int) (/home/michael/Arduino/libraries/M5Stack/src/utility/In_eSPI.cpp:3951).
3946	    else
3947	    {
3948	      while (n--) {tft_Write_16(color);}
3949	    }
3950	  #else
3951	    writeBlock(color, n);
3952	  #endif
3953	#endif
3954	
3955	  spi_end();
(gdb) l *0x400d710e
0x400d710e is in ezHeader::show(String) (/home/michael/Arduino/libraries/M5ez/src/M5ez.cpp:191).
186	}
187	
188	void ezHeader::show(String t /* = "" */) {
189		_shown = true;
190		if (t != "") _title = t;											// only change title if provided
191		m5.lcd.fillRect(0, 0, TFT_W, ez.theme->header_height, ez.theme->header_bgcolor);	// Clear header area
192		for (uint8_t n = 0; n < _widgets.size(); n++) {
193			(_widgets[n].function)(_widgets[n].x, _widgets[n].w);		// Tell all header widgets to draw
194		}
195		ez.canvas.top(ez.theme->header_height);
(gdb) l *0x400d1886
0x400d1886 is in redraw() (/home/michael/Arduino/scan2drive-ui-m5stack/scan2drive-ui-m5stack.ino:113).
108	
109	void redraw(void) {
110	  //ez.screen.clear();
111	  ez.canvas.reset();
112	
113	  ez.header.show("scan2drive");
114	  ez.buttons.show("Lea # Michael # source");
115	
116	  ez.canvas.lmargin(10);

Any idea what I’m doing wrong, or whether this is a bug in M5ez?

I’m using M5ez 2.3.0 on an M5Stack Basic with the following sketch:

#include <M5ez.h>
#include <WiFi.h>
#include <PubSubClient.h>

WiFiClient wificlient;
PubSubClient client(wificlient);

void redraw(void);

void connectToWiFi(void) {
  Serial.println("WiFi: configuring");
  WiFi.mode(WIFI_STA);
  // required to set hostname properly:
  // https://github.com/espressif/arduino-esp32/issues/3438#issuecomment-721428310
  WiFi.config(INADDR_NONE, INADDR_NONE, INADDR_NONE, INADDR_NONE);
  WiFi.setHostname("uiscan2drive");
  WiFi.begin("secret", "secret");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi: connecting...");
    delay(100);
  }
  Serial.print("WiFi: connected: mac=");
  Serial.print(WiFi.macAddress());
  Serial.print(" ip=");
  Serial.print(WiFi.localIP());
  Serial.println("");
}

void taskmqtt(void *pvParameters) {
  for (;;) {
    if (!client.connected()) {
      client.connect("ui_scan2drive" /* clientid */);
      client.subscribe("scan2drive/ui/status");
      client.subscribe("scan2drive/ui/user");
    }

    // Poll PubSubClient for new messages and invoke the callback.
    // Should be called as infrequent as one is willing to delay
    // reacting to MQTT messages.
    // Should not be called too frequently to avoid strain on
    // the network hardware:
    // https://github.com/knolleary/pubsubclient/issues/756#issuecomment-654335096
    client.loop();
    vTaskDelay(pdMS_TO_TICKS(100));
  }
}

// Size determined by how much space we have on the LCD display.
// m5ez does line wrapping for us.
char statusbuffer[140] = {'\0'};

void callback(char* topic, byte* payload, unsigned int length) {
#if 0
  Serial.print("Message arrived [");
  Serial.print(topic);
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]);
  }
  Serial.println();
#endif

  if (strcmp(topic, "scan2drive/ui/status") == 0) {
    int len = length;
    if (len > sizeof(statusbuffer)) {
      len = sizeof(statusbuffer) - 1;
    }
    strncpy(statusbuffer, (const char*)payload, len);
    statusbuffer[len] = '\0';
    if (strcmp(statusbuffer, "powersave") == 0) {
      m5.lcd.setBrightness(0);
    } else {
      m5.lcd.setBrightness(100);
    }
    redraw();
  }
}

void setup() {
  Serial.begin(115200);
  Serial.println("setup");
#include <themes/default.h>
#include <themes/dark.h>
  ezt::setDebug(INFO);
  // ez.begin() calls m5.begin() under the covers:
  ez.begin();
  redraw();

  connectToWiFi();

  client.setServer("dr.lan", 1883);
  client.setCallback(callback);

  xTaskCreatePinnedToCore(taskmqtt, "MQTT", 2048, NULL, 1, NULL, PRO_CPU_NUM);

}

int source = 0;
const char *sourceIdentifiers[] = {
  "usb",
  "airscan",
};
const char *sourceLabels[] = {
  "Fujitsu ScanSnap",
  "Brother (AirScan)",
};

void redraw(void) {
  //ez.screen.clear();
  ez.canvas.reset();

  ez.header.show("scan2drive");
  ez.buttons.show("Lea # Michael # source");

  ez.canvas.lmargin(10);

  ez.canvas.println("");
  ez.canvas.font(&FreeSansBold12pt7b);
  ez.canvas.printf("Source: ");
  ez.canvas.font(&FreeSans12pt7b);
  ez.canvas.println(sourceLabels[source]);

  ez.canvas.font(&FreeSansBold12pt7b);
  ez.canvas.printf("Status: ");
  ez.canvas.font(&FreeSans12pt7b);
  ez.canvas.println(statusbuffer);

  ez.redraw();
}

void loop() {
  String buttonName = ez.buttons.poll();
  if (buttonName == "source") {
    source = (source + 1) % 2;
    redraw();
    return;
  }
  if (buttonName == "Lea" || buttonName == "Michael") {
    String payload = String("{\"user\":\"") +
                     buttonName +
                     String("\", \"source\": \"") +
                     String(sourceIdentifiers[source]) +
                     String("\"}");
    client.publish("scan2drive/cmd/scan", payload.c_str());
  }
}