[io_expanders] Self-heal interrupt-driven expanders when INT stays asserted across the read (#15923)

esphome/components/mcp23016/mcp23016.cpp

@@ -37,7 +37,10 @@ void IRAM_ATTR MCP23016::gpio_intr(MCP23016 *arg) { arg->enable_loop_soon_any_co
 void MCP23016::loop() {
   // Invalidate cache at the start of each loop
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }

esphome/components/mcp23xxx_base/mcp23xxx_base.h

@@ -21,7 +21,10 @@ template<uint8_t N> class MCP23XXXBase : public Component, public gpio_expander:
 
   void loop() override {
     this->reset_pin_cache_();
-    if (this->interrupt_pin_ != nullptr) {
+    // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
+    // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+    // stale state forever; keep looping until the line is released so we self-heal.
+    if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
       this->disable_loop();
     }
   }

esphome/components/pca6416a/pca6416a.cpp

@@ -62,7 +62,10 @@ void IRAM_ATTR PCA6416AComponent::gpio_intr(PCA6416AComponent *arg) { arg->enabl
 void PCA6416AComponent::loop() {
   // Invalidate cache at the start of each loop
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }

esphome/components/pca9554/pca9554.cpp

@@ -50,8 +50,10 @@ void IRAM_ATTR PCA9554Component::gpio_intr(PCA9554Component *arg) { arg->enable_
 void PCA9554Component::loop() {
   // Invalidate the cache so the next digital_read() triggers a fresh I2C read
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
-    // Interrupt-driven: disable loop until next interrupt fires
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }

esphome/components/pcf8574/pcf8574.cpp

@@ -31,8 +31,10 @@ void IRAM_ATTR PCF8574Component::gpio_intr(PCF8574Component *arg) { arg->enable_
 void PCF8574Component::loop() {
   // Invalidate the cache so the next digital_read() triggers a fresh I2C read
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
-    // Interrupt-driven: disable loop until next interrupt fires
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }

esphome/components/pi4ioe5v6408/pi4ioe5v6408.cpp

@@ -82,7 +82,10 @@ void PI4IOE5V6408Component::pin_mode(uint8_t pin, gpio::Flags flags) {
 
 void PI4IOE5V6408Component::loop() {
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }

esphome/components/tca9555/tca9555.cpp

@@ -57,7 +57,10 @@ void TCA9555Component::pin_mode(uint8_t pin, gpio::Flags flags) {
 }
 void TCA9555Component::loop() {
   this->reset_pin_cache_();
-  if (this->interrupt_pin_ != nullptr) {
+  // Only disable the loop once INT has actually gone HIGH. Input transitions that straddle the
+  // I2C read leave INT asserted without re-firing a falling edge, which would strand us with
+  // stale state forever; keep looping until the line is released so we self-heal.
+  if (this->interrupt_pin_ != nullptr && this->interrupt_pin_->digital_read()) {
     this->disable_loop();
   }
 }