Merge branch 'rf_bridge_batch_read' into integration_batch_read

The ack polling loop has a tight timing requirement with
delay_microseconds_safe(1450) between iterations. Snapshotting
available() once could leave partial ack response bytes unread
until after the delay, potentially breaking cold boot timing
on some ld2420 units. Keep batch reads only in loop().

esphome/components/cse7766/cse7766.cpp

@@ -7,7 +7,6 @@ namespace esphome {
 namespace cse7766 {
 
 static const char *const TAG = "cse7766";
-static constexpr size_t CSE7766_RAW_DATA_SIZE = 24;
 
 void CSE7766Component::loop() {
   const uint32_t now = App.get_loop_component_start_time();
@@ -16,25 +15,39 @@ void CSE7766Component::loop() {
     this->raw_data_index_ = 0;
   }
 
-  if (this->available() == 0) {
+  // Early return prevents updating last_transmission_ when no data is available.
+  int avail = this->available();
+  if (avail <= 0) {
     return;
   }
 
   this->last_transmission_ = now;
-  while (this->available() != 0) {
-    this->read_byte(&this->raw_data_[this->raw_data_index_]);
-    if (!this->check_byte_()) {
-      this->raw_data_index_ = 0;
-      this->status_set_warning();
-      continue;
-    }
 
-    if (this->raw_data_index_ == 23) {
-      this->parse_data_();
-      this->status_clear_warning();
+  // Read all available bytes in batches to reduce UART call overhead.
+  // At 4800 baud (~480 bytes/sec) with ~122 Hz loop rate, typically ~4 bytes per call.
+  uint8_t buf[CSE7766_RAW_DATA_SIZE];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
     }
+    avail -= to_read;
 
-    this->raw_data_index_ = (this->raw_data_index_ + 1) % 24;
+    for (size_t i = 0; i < to_read; i++) {
+      this->raw_data_[this->raw_data_index_] = buf[i];
+      if (!this->check_byte_()) {
+        this->raw_data_index_ = 0;
+        this->status_set_warning();
+        continue;
+      }
+
+      if (this->raw_data_index_ == CSE7766_RAW_DATA_SIZE - 1) {
+        this->parse_data_();
+        this->status_clear_warning();
+      }
+
+      this->raw_data_index_ = (this->raw_data_index_ + 1) % CSE7766_RAW_DATA_SIZE;
+    }
   }
 }
 
@@ -53,14 +66,15 @@ bool CSE7766Component::check_byte_() {
     return true;
   }
 
-  if (index == 23) {
+  if (index == CSE7766_RAW_DATA_SIZE - 1) {
     uint8_t checksum = 0;
-    for (uint8_t i = 2; i < 23; i++) {
+    for (uint8_t i = 2; i < CSE7766_RAW_DATA_SIZE - 1; i++) {
       checksum += this->raw_data_[i];
     }
 
-    if (checksum != this->raw_data_[23]) {
-      ESP_LOGW(TAG, "Invalid checksum from CSE7766: 0x%02X != 0x%02X", checksum, this->raw_data_[23]);
+    if (checksum != this->raw_data_[CSE7766_RAW_DATA_SIZE - 1]) {
+      ESP_LOGW(TAG, "Invalid checksum from CSE7766: 0x%02X != 0x%02X", checksum,
+               this->raw_data_[CSE7766_RAW_DATA_SIZE - 1]);
       return false;
     }
     return true;

esphome/components/cse7766/cse7766.h

@@ -8,6 +8,8 @@
 namespace esphome {
 namespace cse7766 {
 
+static constexpr size_t CSE7766_RAW_DATA_SIZE = 24;
+
 class CSE7766Component : public Component, public uart::UARTDevice {
  public:
   void set_voltage_sensor(sensor::Sensor *voltage_sensor) { voltage_sensor_ = voltage_sensor; }
@@ -33,7 +35,7 @@ class CSE7766Component : public Component, public uart::UARTDevice {
                          this->raw_data_[start_index + 2]);
   }
 
-  uint8_t raw_data_[24];
+  uint8_t raw_data_[CSE7766_RAW_DATA_SIZE];
   uint8_t raw_data_index_{0};
   uint32_t last_transmission_{0};
   sensor::Sensor *voltage_sensor_{nullptr};

esphome/components/dfplayer/dfplayer.cpp

@@ -1,4 +1,5 @@
 #include "dfplayer.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 namespace esphome {
@@ -131,140 +132,149 @@ void DFPlayer::send_cmd_(uint8_t cmd, uint16_t argument) {
 }
 
 void DFPlayer::loop() {
-  // Read message
-  while (this->available()) {
-    uint8_t byte;
-    this->read_byte(&byte);
-
-    if (this->read_pos_ == DFPLAYER_READ_BUFFER_LENGTH)
-      this->read_pos_ = 0;
-
-    switch (this->read_pos_) {
-      case 0:  // Start mark
-        if (byte != 0x7E)
-          continue;
-        break;
-      case 1:  // Version
-        if (byte != 0xFF) {
-          ESP_LOGW(TAG, "Expected Version 0xFF, got %#02x", byte);
-          this->read_pos_ = 0;
-          continue;
-        }
-        break;
-      case 2:  // Buffer length
-        if (byte != 0x06) {
-          ESP_LOGW(TAG, "Expected Buffer length 0x06, got %#02x", byte);
-          this->read_pos_ = 0;
-          continue;
-        }
-        break;
-      case 9:  // End byte
-#ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
-        char byte_sequence[100];
-        byte_sequence[0] = '\0';
-        for (size_t i = 0; i < this->read_pos_ + 1; ++i) {
-          snprintf(byte_sequence + strlen(byte_sequence), sizeof(byte_sequence) - strlen(byte_sequence), "%02X ",
-                   this->read_buffer_[i]);
-        }
-        ESP_LOGVV(TAG, "Received byte sequence: %s", byte_sequence);
-#endif
-        if (byte != 0xEF) {
-          ESP_LOGW(TAG, "Expected end byte 0xEF, got %#02x", byte);
-          this->read_pos_ = 0;
-          continue;
-        }
-        // Parse valid received command
-        uint8_t cmd = this->read_buffer_[3];
-        uint16_t argument = (this->read_buffer_[5] << 8) | this->read_buffer_[6];
-
-        ESP_LOGV(TAG, "Received message cmd: %#02x arg %#04x", cmd, argument);
-
-        switch (cmd) {
-          case 0x3A:
-            if (argument == 1) {
-              ESP_LOGI(TAG, "USB loaded");
-            } else if (argument == 2) {
-              ESP_LOGI(TAG, "TF Card loaded");
-            }
-            break;
-          case 0x3B:
-            if (argument == 1) {
-              ESP_LOGI(TAG, "USB unloaded");
-            } else if (argument == 2) {
-              ESP_LOGI(TAG, "TF Card unloaded");
-            }
-            break;
-          case 0x3F:
-            if (argument == 1) {
-              ESP_LOGI(TAG, "USB available");
-            } else if (argument == 2) {
-              ESP_LOGI(TAG, "TF Card available");
-            } else if (argument == 3) {
-              ESP_LOGI(TAG, "USB, TF Card available");
-            }
-            break;
-          case 0x40:
-            ESP_LOGV(TAG, "Nack");
-            this->ack_set_is_playing_ = false;
-            this->ack_reset_is_playing_ = false;
-            switch (argument) {
-              case 0x01:
-                ESP_LOGE(TAG, "Module is busy or uninitialized");
-                break;
-              case 0x02:
-                ESP_LOGE(TAG, "Module is in sleep mode");
-                break;
-              case 0x03:
-                ESP_LOGE(TAG, "Serial receive error");
-                break;
-              case 0x04:
-                ESP_LOGE(TAG, "Checksum incorrect");
-                break;
-              case 0x05:
-                ESP_LOGE(TAG, "Specified track is out of current track scope");
-                this->is_playing_ = false;
-                break;
-              case 0x06:
-                ESP_LOGE(TAG, "Specified track is not found");
-                this->is_playing_ = false;
-                break;
-              case 0x07:
-                ESP_LOGE(TAG, "Insertion error (an inserting operation only can be done when a track is being played)");
-                break;
-              case 0x08:
-                ESP_LOGE(TAG, "SD card reading failed (SD card pulled out or damaged)");
-                break;
-              case 0x09:
-                ESP_LOGE(TAG, "Entered into sleep mode");
-                this->is_playing_ = false;
-                break;
-            }
-            break;
-          case 0x41:
-            ESP_LOGV(TAG, "Ack ok");
-            this->is_playing_ |= this->ack_set_is_playing_;
-            this->is_playing_ &= !this->ack_reset_is_playing_;
-            this->ack_set_is_playing_ = false;
-            this->ack_reset_is_playing_ = false;
-            break;
-          case 0x3C:
-            ESP_LOGV(TAG, "Playback finished (USB drive)");
-            this->is_playing_ = false;
-            this->on_finished_playback_callback_.call();
-          case 0x3D:
-            ESP_LOGV(TAG, "Playback finished (SD card)");
-            this->is_playing_ = false;
-            this->on_finished_playback_callback_.call();
-            break;
-          default:
-            ESP_LOGE(TAG, "Received unknown cmd %#02x arg %#04x", cmd, argument);
-        }
-        this->sent_cmd_ = 0;
-        this->read_pos_ = 0;
-        continue;
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+    for (size_t bi = 0; bi < to_read; bi++) {
+      uint8_t byte = buf[bi];
+
+      if (this->read_pos_ == DFPLAYER_READ_BUFFER_LENGTH)
+        this->read_pos_ = 0;
+
+      switch (this->read_pos_) {
+        case 0:  // Start mark
+          if (byte != 0x7E)
+            continue;
+          break;
+        case 1:  // Version
+          if (byte != 0xFF) {
+            ESP_LOGW(TAG, "Expected Version 0xFF, got %#02x", byte);
+            this->read_pos_ = 0;
+            continue;
+          }
+          break;
+        case 2:  // Buffer length
+          if (byte != 0x06) {
+            ESP_LOGW(TAG, "Expected Buffer length 0x06, got %#02x", byte);
+            this->read_pos_ = 0;
+            continue;
+          }
+          break;
+        case 9:  // End byte
+#ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
+          char byte_sequence[100];
+          byte_sequence[0] = '\0';
+          for (size_t i = 0; i < this->read_pos_ + 1; ++i) {
+            snprintf(byte_sequence + strlen(byte_sequence), sizeof(byte_sequence) - strlen(byte_sequence), "%02X ",
+                     this->read_buffer_[i]);
+          }
+          ESP_LOGVV(TAG, "Received byte sequence: %s", byte_sequence);
+#endif
+          if (byte != 0xEF) {
+            ESP_LOGW(TAG, "Expected end byte 0xEF, got %#02x", byte);
+            this->read_pos_ = 0;
+            continue;
+          }
+          // Parse valid received command
+          uint8_t cmd = this->read_buffer_[3];
+          uint16_t argument = (this->read_buffer_[5] << 8) | this->read_buffer_[6];
+
+          ESP_LOGV(TAG, "Received message cmd: %#02x arg %#04x", cmd, argument);
+
+          switch (cmd) {
+            case 0x3A:
+              if (argument == 1) {
+                ESP_LOGI(TAG, "USB loaded");
+              } else if (argument == 2) {
+                ESP_LOGI(TAG, "TF Card loaded");
+              }
+              break;
+            case 0x3B:
+              if (argument == 1) {
+                ESP_LOGI(TAG, "USB unloaded");
+              } else if (argument == 2) {
+                ESP_LOGI(TAG, "TF Card unloaded");
+              }
+              break;
+            case 0x3F:
+              if (argument == 1) {
+                ESP_LOGI(TAG, "USB available");
+              } else if (argument == 2) {
+                ESP_LOGI(TAG, "TF Card available");
+              } else if (argument == 3) {
+                ESP_LOGI(TAG, "USB, TF Card available");
+              }
+              break;
+            case 0x40:
+              ESP_LOGV(TAG, "Nack");
+              this->ack_set_is_playing_ = false;
+              this->ack_reset_is_playing_ = false;
+              switch (argument) {
+                case 0x01:
+                  ESP_LOGE(TAG, "Module is busy or uninitialized");
+                  break;
+                case 0x02:
+                  ESP_LOGE(TAG, "Module is in sleep mode");
+                  break;
+                case 0x03:
+                  ESP_LOGE(TAG, "Serial receive error");
+                  break;
+                case 0x04:
+                  ESP_LOGE(TAG, "Checksum incorrect");
+                  break;
+                case 0x05:
+                  ESP_LOGE(TAG, "Specified track is out of current track scope");
+                  this->is_playing_ = false;
+                  break;
+                case 0x06:
+                  ESP_LOGE(TAG, "Specified track is not found");
+                  this->is_playing_ = false;
+                  break;
+                case 0x07:
+                  ESP_LOGE(TAG,
+                           "Insertion error (an inserting operation only can be done when a track is being played)");
+                  break;
+                case 0x08:
+                  ESP_LOGE(TAG, "SD card reading failed (SD card pulled out or damaged)");
+                  break;
+                case 0x09:
+                  ESP_LOGE(TAG, "Entered into sleep mode");
+                  this->is_playing_ = false;
+                  break;
+              }
+              break;
+            case 0x41:
+              ESP_LOGV(TAG, "Ack ok");
+              this->is_playing_ |= this->ack_set_is_playing_;
+              this->is_playing_ &= !this->ack_reset_is_playing_;
+              this->ack_set_is_playing_ = false;
+              this->ack_reset_is_playing_ = false;
+              break;
+            case 0x3C:
+              ESP_LOGV(TAG, "Playback finished (USB drive)");
+              this->is_playing_ = false;
+              this->on_finished_playback_callback_.call();
+            case 0x3D:
+              ESP_LOGV(TAG, "Playback finished (SD card)");
+              this->is_playing_ = false;
+              this->on_finished_playback_callback_.call();
+              break;
+            default:
+              ESP_LOGE(TAG, "Received unknown cmd %#02x arg %#04x", cmd, argument);
+          }
+          this->sent_cmd_ = 0;
+          this->read_pos_ = 0;
+          continue;
+      }
+      this->read_buffer_[this->read_pos_] = byte;
+      this->read_pos_++;
     }
-    this->read_buffer_[this->read_pos_] = byte;
-    this->read_pos_++;
   }
 }
 void DFPlayer::dump_config() {

esphome/components/dlms_meter/dlms_meter.cpp

@@ -28,15 +28,28 @@ void DlmsMeterComponent::dump_config() {
 
 void DlmsMeterComponent::loop() {
   // Read while data is available, netznoe uses two frames so allow 2x max frame length
-  while (this->available()) {
-    if (this->receive_buffer_.size() >= MBUS_MAX_FRAME_LENGTH * 2) {
+  int avail = this->available();
+  if (avail > 0) {
+    size_t remaining = MBUS_MAX_FRAME_LENGTH * 2 - this->receive_buffer_.size();
+    if (remaining == 0) {
       ESP_LOGW(TAG, "Receive buffer full, dropping remaining bytes");
-      break;
+    } else {
+      // Read all available bytes in batches to reduce UART call overhead.
+      // Cap reads to remaining buffer capacity.
+      if (static_cast<size_t>(avail) > remaining) {
+        avail = remaining;
+      }
+      uint8_t buf[64];
+      while (avail > 0) {
+        size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+        if (!this->read_array(buf, to_read)) {
+          break;
+        }
+        avail -= to_read;
+        this->receive_buffer_.insert(this->receive_buffer_.end(), buf, buf + to_read);
+        this->last_read_ = millis();
+      }
     }
-    uint8_t c;
-    this->read_byte(&c);
-    this->receive_buffer_.push_back(c);
-    this->last_read_ = millis();
   }
 
   if (!this->receive_buffer_.empty() && millis() - this->last_read_ > this->read_timeout_) {

esphome/components/dsmr/dsmr.cpp

@@ -40,9 +40,7 @@ bool Dsmr::ready_to_request_data_() {
       this->start_requesting_data_();
     }
     if (!this->requesting_data_) {
-      while (this->available()) {
-        this->read();
-      }
+      this->drain_rx_buffer_();
     }
   }
   return this->requesting_data_;
@@ -115,13 +113,21 @@ void Dsmr::stop_requesting_data_() {
     } else {
       ESP_LOGV(TAG, "Stop reading data from P1 port");
     }
-    while (this->available()) {
-      this->read();
-    }
+    this->drain_rx_buffer_();
     this->requesting_data_ = false;
   }
 }
 
+void Dsmr::drain_rx_buffer_() {
+  uint8_t buf[64];
+  int avail;
+  while ((avail = this->available()) > 0) {
+    if (!this->read_array(buf, std::min(static_cast<size_t>(avail), sizeof(buf)))) {
+      break;
+    }
+  }
+}
+
 void Dsmr::reset_telegram_() {
   this->header_found_ = false;
   this->footer_found_ = false;
@@ -133,120 +139,144 @@ void Dsmr::reset_telegram_() {
 
 void Dsmr::receive_telegram_() {
   while (this->available_within_timeout_()) {
-    const char c = this->read();
+    // Read all available bytes in batches to reduce UART call overhead.
+    uint8_t buf[64];
+    int avail = this->available();
+    while (avail > 0) {
+      size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+      if (!this->read_array(buf, to_read))
+        return;
+      avail -= to_read;
 
-    // Find a new telegram header, i.e. forward slash.
-    if (c == '/') {
-      ESP_LOGV(TAG, "Header of telegram found");
-      this->reset_telegram_();
-      this->header_found_ = true;
-    }
-    if (!this->header_found_)
-      continue;
+      for (size_t i = 0; i < to_read; i++) {
+        const char c = static_cast<char>(buf[i]);
 
-    // Check for buffer overflow.
-    if (this->bytes_read_ >= this->max_telegram_len_) {
-      this->reset_telegram_();
-      ESP_LOGE(TAG, "Error: telegram larger than buffer (%d bytes)", this->max_telegram_len_);
-      return;
-    }
+        // Find a new telegram header, i.e. forward slash.
+        if (c == '/') {
+          ESP_LOGV(TAG, "Header of telegram found");
+          this->reset_telegram_();
+          this->header_found_ = true;
+        }
+        if (!this->header_found_)
+          continue;
 
-    // Some v2.2 or v3 meters will send a new value which starts with '('
-    // in a new line, while the value belongs to the previous ObisId. For
-    // proper parsing, remove these new line characters.
-    if (c == '(') {
-      while (true) {
-        auto previous_char = this->telegram_[this->bytes_read_ - 1];
-        if (previous_char == '\n' || previous_char == '\r') {
-          this->bytes_read_--;
-        } else {
-          break;
+        // Check for buffer overflow.
+        if (this->bytes_read_ >= this->max_telegram_len_) {
+          this->reset_telegram_();
+          ESP_LOGE(TAG, "Error: telegram larger than buffer (%d bytes)", this->max_telegram_len_);
+          return;
+        }
+
+        // Some v2.2 or v3 meters will send a new value which starts with '('
+        // in a new line, while the value belongs to the previous ObisId. For
+        // proper parsing, remove these new line characters.
+        if (c == '(') {
+          while (true) {
+            auto previous_char = this->telegram_[this->bytes_read_ - 1];
+            if (previous_char == '\n' || previous_char == '\r') {
+              this->bytes_read_--;
+            } else {
+              break;
+            }
+          }
+        }
+
+        // Store the byte in the buffer.
+        this->telegram_[this->bytes_read_] = c;
+        this->bytes_read_++;
+
+        // Check for a footer, i.e. exclamation mark, followed by a hex checksum.
+        if (c == '!') {
+          ESP_LOGV(TAG, "Footer of telegram found");
+          this->footer_found_ = true;
+          continue;
+        }
+        // Check for the end of the hex checksum, i.e. a newline.
+        if (this->footer_found_ && c == '\n') {
+          // Parse the telegram and publish sensor values.
+          this->parse_telegram();
+          this->reset_telegram_();
+          return;
         }
       }
     }
-
-    // Store the byte in the buffer.
-    this->telegram_[this->bytes_read_] = c;
-    this->bytes_read_++;
-
-    // Check for a footer, i.e. exclamation mark, followed by a hex checksum.
-    if (c == '!') {
-      ESP_LOGV(TAG, "Footer of telegram found");
-      this->footer_found_ = true;
-      continue;
-    }
-    // Check for the end of the hex checksum, i.e. a newline.
-    if (this->footer_found_ && c == '\n') {
-      // Parse the telegram and publish sensor values.
-      this->parse_telegram();
-      this->reset_telegram_();
-      return;
-    }
   }
 }
 
 void Dsmr::receive_encrypted_telegram_() {
   while (this->available_within_timeout_()) {
-    const char c = this->read();
+    // Read all available bytes in batches to reduce UART call overhead.
+    uint8_t buf[64];
+    int avail = this->available();
+    while (avail > 0) {
+      size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+      if (!this->read_array(buf, to_read))
+        return;
+      avail -= to_read;
 
-    // Find a new telegram start byte.
-    if (!this->header_found_) {
-      if ((uint8_t) c != 0xDB) {
-        continue;
+      for (size_t i = 0; i < to_read; i++) {
+        const char c = static_cast<char>(buf[i]);
+
+        // Find a new telegram start byte.
+        if (!this->header_found_) {
+          if ((uint8_t) c != 0xDB) {
+            continue;
+          }
+          ESP_LOGV(TAG, "Start byte 0xDB of encrypted telegram found");
+          this->reset_telegram_();
+          this->header_found_ = true;
+        }
+
+        // Check for buffer overflow.
+        if (this->crypt_bytes_read_ >= this->max_telegram_len_) {
+          this->reset_telegram_();
+          ESP_LOGE(TAG, "Error: encrypted telegram larger than buffer (%d bytes)", this->max_telegram_len_);
+          return;
+        }
+
+        // Store the byte in the buffer.
+        this->crypt_telegram_[this->crypt_bytes_read_] = c;
+        this->crypt_bytes_read_++;
+
+        // Read the length of the incoming encrypted telegram.
+        if (this->crypt_telegram_len_ == 0 && this->crypt_bytes_read_ > 20) {
+          // Complete header + data bytes
+          this->crypt_telegram_len_ = 13 + (this->crypt_telegram_[11] << 8 | this->crypt_telegram_[12]);
+          ESP_LOGV(TAG, "Encrypted telegram length: %d bytes", this->crypt_telegram_len_);
+        }
+
+        // Check for the end of the encrypted telegram.
+        if (this->crypt_telegram_len_ == 0 || this->crypt_bytes_read_ != this->crypt_telegram_len_) {
+          continue;
+        }
+        ESP_LOGV(TAG, "End of encrypted telegram found");
+
+        // Decrypt the encrypted telegram.
+        GCM<AES128> *gcmaes128{new GCM<AES128>()};
+        gcmaes128->setKey(this->decryption_key_.data(), gcmaes128->keySize());
+        // the iv is 8 bytes of the system title + 4 bytes frame counter
+        // system title is at byte 2 and frame counter at byte 15
+        for (int i = 10; i < 14; i++)
+          this->crypt_telegram_[i] = this->crypt_telegram_[i + 4];
+        constexpr uint16_t iv_size{12};
+        gcmaes128->setIV(&this->crypt_telegram_[2], iv_size);
+        gcmaes128->decrypt(reinterpret_cast<uint8_t *>(this->telegram_),
+                           // the ciphertext start at byte 18
+                           &this->crypt_telegram_[18],
+                           // cipher size
+                           this->crypt_bytes_read_ - 17);
+        delete gcmaes128;  // NOLINT(cppcoreguidelines-owning-memory)
+
+        this->bytes_read_ = strnlen(this->telegram_, this->max_telegram_len_);
+        ESP_LOGV(TAG, "Decrypted telegram size: %d bytes", this->bytes_read_);
+        ESP_LOGVV(TAG, "Decrypted telegram: %s", this->telegram_);
+
+        // Parse the decrypted telegram and publish sensor values.
+        this->parse_telegram();
+        this->reset_telegram_();
+        return;
       }
-      ESP_LOGV(TAG, "Start byte 0xDB of encrypted telegram found");
-      this->reset_telegram_();
-      this->header_found_ = true;
     }
-
-    // Check for buffer overflow.
-    if (this->crypt_bytes_read_ >= this->max_telegram_len_) {
-      this->reset_telegram_();
-      ESP_LOGE(TAG, "Error: encrypted telegram larger than buffer (%d bytes)", this->max_telegram_len_);
-      return;
-    }
-
-    // Store the byte in the buffer.
-    this->crypt_telegram_[this->crypt_bytes_read_] = c;
-    this->crypt_bytes_read_++;
-
-    // Read the length of the incoming encrypted telegram.
-    if (this->crypt_telegram_len_ == 0 && this->crypt_bytes_read_ > 20) {
-      // Complete header + data bytes
-      this->crypt_telegram_len_ = 13 + (this->crypt_telegram_[11] << 8 | this->crypt_telegram_[12]);
-      ESP_LOGV(TAG, "Encrypted telegram length: %d bytes", this->crypt_telegram_len_);
-    }
-
-    // Check for the end of the encrypted telegram.
-    if (this->crypt_telegram_len_ == 0 || this->crypt_bytes_read_ != this->crypt_telegram_len_) {
-      continue;
-    }
-    ESP_LOGV(TAG, "End of encrypted telegram found");
-
-    // Decrypt the encrypted telegram.
-    GCM<AES128> *gcmaes128{new GCM<AES128>()};
-    gcmaes128->setKey(this->decryption_key_.data(), gcmaes128->keySize());
-    // the iv is 8 bytes of the system title + 4 bytes frame counter
-    // system title is at byte 2 and frame counter at byte 15
-    for (int i = 10; i < 14; i++)
-      this->crypt_telegram_[i] = this->crypt_telegram_[i + 4];
-    constexpr uint16_t iv_size{12};
-    gcmaes128->setIV(&this->crypt_telegram_[2], iv_size);
-    gcmaes128->decrypt(reinterpret_cast<uint8_t *>(this->telegram_),
-                       // the ciphertext start at byte 18
-                       &this->crypt_telegram_[18],
-                       // cipher size
-                       this->crypt_bytes_read_ - 17);
-    delete gcmaes128;  // NOLINT(cppcoreguidelines-owning-memory)
-
-    this->bytes_read_ = strnlen(this->telegram_, this->max_telegram_len_);
-    ESP_LOGV(TAG, "Decrypted telegram size: %d bytes", this->bytes_read_);
-    ESP_LOGVV(TAG, "Decrypted telegram: %s", this->telegram_);
-
-    // Parse the decrypted telegram and publish sensor values.
-    this->parse_telegram();
-    this->reset_telegram_();
-    return;
   }
 }
 

esphome/components/dsmr/dsmr.h

@@ -85,6 +85,7 @@ class Dsmr : public Component, public uart::UARTDevice {
   void receive_telegram_();
   void receive_encrypted_telegram_();
   void reset_telegram_();
+  void drain_rx_buffer_();
 
   /// Wait for UART data to become available within the read timeout.
   ///

esphome/components/ld2410/ld2410.cpp

@@ -275,8 +275,19 @@ void LD2410Component::restart_and_read_all_info() {
 }
 
 void LD2410Component::loop() {
-  while (this->available()) {
-    this->readline_(this->read());
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[MAX_LINE_LENGTH];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      this->readline_(buf[i]);
+    }
   }
 }
 

esphome/components/ld2412/ld2412.cpp

@@ -310,8 +310,19 @@ void LD2412Component::restart_and_read_all_info() {
 }
 
 void LD2412Component::loop() {
-  while (this->available()) {
-    this->readline_(this->read());
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[MAX_LINE_LENGTH];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      this->readline_(buf[i]);
+    }
   }
 }
 

esphome/components/ld2420/ld2420.cpp

@@ -335,9 +335,10 @@ void LD2420Component::revert_config_action() {
 
 void LD2420Component::loop() {
   // If there is a active send command do not process it here, the send command call will handle it.
-  while (!this->cmd_active_ && this->available()) {
-    this->readline_(this->read(), this->buffer_data_, MAX_LINE_LENGTH);
+  if (this->cmd_active_) {
+    return;
   }
+  this->read_batch_(this->buffer_data_);
 }
 
 void LD2420Component::update_radar_data(uint16_t const *gate_energy, uint8_t sample_number) {
@@ -539,6 +540,23 @@ void LD2420Component::handle_simple_mode_(const uint8_t *inbuf, int len) {
   }
 }
 
+void LD2420Component::read_batch_(std::span<uint8_t, MAX_LINE_LENGTH> buffer) {
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[MAX_LINE_LENGTH];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      this->readline_(buf[i], buffer.data(), buffer.size());
+    }
+  }
+}
+
 void LD2420Component::handle_ack_data_(uint8_t *buffer, int len) {
   this->cmd_reply_.command = buffer[CMD_FRAME_COMMAND];
   this->cmd_reply_.length = buffer[CMD_FRAME_DATA_LENGTH];

esphome/components/ld2420/ld2420.h

@@ -4,6 +4,7 @@
 #include "esphome/components/uart/uart.h"
 #include "esphome/core/automation.h"
 #include "esphome/core/helpers.h"
+#include <span>
 #ifdef USE_TEXT_SENSOR
 #include "esphome/components/text_sensor/text_sensor.h"
 #endif
@@ -165,6 +166,7 @@ class LD2420Component : public Component, public uart::UARTDevice {
   void handle_energy_mode_(uint8_t *buffer, int len);
   void handle_ack_data_(uint8_t *buffer, int len);
   void readline_(int rx_data, uint8_t *buffer, int len);
+  void read_batch_(std::span<uint8_t, MAX_LINE_LENGTH> buffer);
   void set_calibration_(bool state) { this->calibration_ = state; };
   bool get_calibration_() { return this->calibration_; };
 

esphome/components/ld2450/ld2450.cpp

@@ -276,8 +276,19 @@ void LD2450Component::dump_config() {
 }
 
 void LD2450Component::loop() {
-  while (this->available()) {
-    this->readline_(this->read());
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[MAX_LINE_LENGTH];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      this->readline_(buf[i]);
+    }
   }
 }
 

esphome/components/modbus/modbus.cpp

@@ -19,16 +19,25 @@ void Modbus::setup() {
 void Modbus::loop() {
   const uint32_t now = App.get_loop_component_start_time();
 
-  while (this->available()) {
-    uint8_t byte;
-    this->read_byte(&byte);
-    if (this->parse_modbus_byte_(byte)) {
-      this->last_modbus_byte_ = now;
-    } else {
-      size_t at = this->rx_buffer_.size();
-      if (at > 0) {
-        ESP_LOGV(TAG, "Clearing buffer of %d bytes - parse failed", at);
-        this->rx_buffer_.clear();
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      if (this->parse_modbus_byte_(buf[i])) {
+        this->last_modbus_byte_ = now;
+      } else {
+        size_t at = this->rx_buffer_.size();
+        if (at > 0) {
+          ESP_LOGV(TAG, "Clearing buffer of %d bytes - parse failed", at);
+          this->rx_buffer_.clear();
+        }
       }
     }
   }

esphome/components/nextion/nextion.cpp

@@ -397,11 +397,17 @@ bool Nextion::remove_from_q_(bool report_empty) {
 }
 
 void Nextion::process_serial_() {
-  uint8_t d;
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
 
-  while (this->available()) {
-    read_byte(&d);
-    this->command_data_ += d;
+    this->command_data_.append(reinterpret_cast<const char *>(buf), to_read);
   }
 }
 // nextion.tech/instruction-set/

esphome/components/pipsolar/pipsolar.cpp

@@ -13,9 +13,12 @@ void Pipsolar::setup() {
 }
 
 void Pipsolar::empty_uart_buffer_() {
-  uint8_t byte;
-  while (this->available()) {
-    this->read_byte(&byte);
+  uint8_t buf[64];
+  int avail;
+  while ((avail = this->available()) > 0) {
+    if (!this->read_array(buf, std::min(static_cast<size_t>(avail), sizeof(buf)))) {
+      break;
+    }
   }
 }
 
@@ -94,32 +97,47 @@ void Pipsolar::loop() {
   }
 
   if (this->state_ == STATE_COMMAND || this->state_ == STATE_POLL) {
-    while (this->available()) {
-      uint8_t byte;
-      this->read_byte(&byte);
-
-      // make sure data and null terminator fit in buffer
-      if (this->read_pos_ >= PIPSOLAR_READ_BUFFER_LENGTH - 1) {
-        this->read_pos_ = 0;
-        this->empty_uart_buffer_();
-        ESP_LOGW(TAG, "response data too long, discarding.");
+    int avail = this->available();
+    while (avail > 0) {
+      uint8_t buf[64];
+      size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+      if (!this->read_array(buf, to_read)) {
         break;
       }
-      this->read_buffer_[this->read_pos_] = byte;
-      this->read_pos_++;
+      avail -= to_read;
+      bool done = false;
+      for (size_t i = 0; i < to_read; i++) {
+        uint8_t byte = buf[i];
 
-      // end of answer
-      if (byte == 0x0D) {
-        this->read_buffer_[this->read_pos_] = 0;
-        this->empty_uart_buffer_();
-        if (this->state_ == STATE_POLL) {
-          this->state_ = STATE_POLL_COMPLETE;
+        // make sure data and null terminator fit in buffer
+        if (this->read_pos_ >= PIPSOLAR_READ_BUFFER_LENGTH - 1) {
+          this->read_pos_ = 0;
+          this->empty_uart_buffer_();
+          ESP_LOGW(TAG, "response data too long, discarding.");
+          done = true;
+          break;
         }
-        if (this->state_ == STATE_COMMAND) {
-          this->state_ = STATE_COMMAND_COMPLETE;
+        this->read_buffer_[this->read_pos_] = byte;
+        this->read_pos_++;
+
+        // end of answer
+        if (byte == 0x0D) {
+          this->read_buffer_[this->read_pos_] = 0;
+          this->empty_uart_buffer_();
+          if (this->state_ == STATE_POLL) {
+            this->state_ = STATE_POLL_COMPLETE;
+          }
+          if (this->state_ == STATE_COMMAND) {
+            this->state_ = STATE_COMMAND_COMPLETE;
+          }
+          done = true;
+          break;
         }
       }
-    }  // available
+      if (done) {
+        break;
+      }
+    }
   }
   if (this->state_ == STATE_COMMAND) {
     if (millis() - this->command_start_millis_ > esphome::pipsolar::Pipsolar::COMMAND_TIMEOUT) {

esphome/components/pylontech/pylontech.cpp

@@ -56,17 +56,23 @@ void PylontechComponent::setup() {
 void PylontechComponent::update() { this->write_str("pwr\n"); }
 
 void PylontechComponent::loop() {
-  if (this->available() > 0) {
+  int avail = this->available();
+  if (avail > 0) {
     // pylontech sends a lot of data very suddenly
     // we need to quickly put it all into our own buffer, otherwise the uart's buffer will overflow
-    uint8_t data;
     int recv = 0;
-    while (this->available() > 0) {
-      if (this->read_byte(&data)) {
-        buffer_[buffer_index_write_] += (char) data;
-        recv++;
-        if (buffer_[buffer_index_write_].back() == static_cast<char>(ASCII_LF) ||
-            buffer_[buffer_index_write_].length() >= MAX_DATA_LENGTH_BYTES) {
+    uint8_t buf[64];
+    while (avail > 0) {
+      size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+      if (!this->read_array(buf, to_read)) {
+        break;
+      }
+      avail -= to_read;
+      recv += to_read;
+
+      for (size_t i = 0; i < to_read; i++) {
+        buffer_[buffer_index_write_] += (char) buf[i];
+        if (buf[i] == ASCII_LF || buffer_[buffer_index_write_].length() >= MAX_DATA_LENGTH_BYTES) {
           // complete line received
           buffer_index_write_ = (buffer_index_write_ + 1) % NUM_BUFFERS;
         }

esphome/components/rd03d/rd03d.cpp

@@ -1,4 +1,5 @@
 #include "rd03d.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cmath>
 
@@ -80,37 +81,47 @@ void RD03DComponent::dump_config() {
 }
 
 void RD03DComponent::loop() {
-  while (this->available()) {
-    uint8_t byte = this->read();
-    ESP_LOGVV(TAG, "Received byte: 0x%02X, buffer_pos: %d", byte, this->buffer_pos_);
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+    for (size_t i = 0; i < to_read; i++) {
+      uint8_t byte = buf[i];
+      ESP_LOGVV(TAG, "Received byte: 0x%02X, buffer_pos: %d", byte, this->buffer_pos_);
 
-    // Check if we're looking for frame header
-    if (this->buffer_pos_ < FRAME_HEADER_SIZE) {
-      if (byte == FRAME_HEADER[this->buffer_pos_]) {
-        this->buffer_[this->buffer_pos_++] = byte;
-      } else if (byte == FRAME_HEADER[0]) {
-        // Start over if we see a potential new header
-        this->buffer_[0] = byte;
-        this->buffer_pos_ = 1;
-      } else {
+      // Check if we're looking for frame header
+      if (this->buffer_pos_ < FRAME_HEADER_SIZE) {
+        if (byte == FRAME_HEADER[this->buffer_pos_]) {
+          this->buffer_[this->buffer_pos_++] = byte;
+        } else if (byte == FRAME_HEADER[0]) {
+          // Start over if we see a potential new header
+          this->buffer_[0] = byte;
+          this->buffer_pos_ = 1;
+        } else {
+          this->buffer_pos_ = 0;
+        }
+        continue;
+      }
+
+      // Accumulate data bytes
+      this->buffer_[this->buffer_pos_++] = byte;
+
+      // Check if we have a complete frame
+      if (this->buffer_pos_ == FRAME_SIZE) {
+        // Validate footer
+        if (this->buffer_[FRAME_SIZE - 2] == FRAME_FOOTER[0] && this->buffer_[FRAME_SIZE - 1] == FRAME_FOOTER[1]) {
+          this->process_frame_();
+        } else {
+          ESP_LOGW(TAG, "Invalid frame footer: 0x%02X 0x%02X (expected 0x55 0xCC)", this->buffer_[FRAME_SIZE - 2],
+                   this->buffer_[FRAME_SIZE - 1]);
+        }
         this->buffer_pos_ = 0;
       }
-      continue;
-    }
-
-    // Accumulate data bytes
-    this->buffer_[this->buffer_pos_++] = byte;
-
-    // Check if we have a complete frame
-    if (this->buffer_pos_ == FRAME_SIZE) {
-      // Validate footer
-      if (this->buffer_[FRAME_SIZE - 2] == FRAME_FOOTER[0] && this->buffer_[FRAME_SIZE - 1] == FRAME_FOOTER[1]) {
-        this->process_frame_();
-      } else {
-        ESP_LOGW(TAG, "Invalid frame footer: 0x%02X 0x%02X (expected 0x55 0xCC)", this->buffer_[FRAME_SIZE - 2],
-                 this->buffer_[FRAME_SIZE - 1]);
-      }
-      this->buffer_pos_ = 0;
     }
   }
 }

esphome/components/rf_bridge/rf_bridge.cpp

@@ -136,14 +136,21 @@ void RFBridgeComponent::loop() {
     this->last_bridge_byte_ = now;
   }
 
-  while (this->available()) {
-    uint8_t byte;
-    this->read_byte(&byte);
-    if (this->parse_bridge_byte_(byte)) {
-      ESP_LOGVV(TAG, "Parsed: 0x%02X", byte);
-      this->last_bridge_byte_ = now;
-    } else {
-      this->rx_buffer_.clear();
+  int avail = this->available();
+  while (avail > 0) {
+    uint8_t buf[64];
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+    for (size_t i = 0; i < to_read; i++) {
+      if (this->parse_bridge_byte_(buf[i])) {
+        ESP_LOGVV(TAG, "Parsed: 0x%02X", buf[i]);
+        this->last_bridge_byte_ = now;
+      } else {
+        this->rx_buffer_.clear();
+      }
     }
   }
 }

esphome/components/seeed_mr24hpc1/seeed_mr24hpc1.cpp

@@ -106,12 +106,19 @@ void MR24HPC1Component::update_() {
 
 // main loop
 void MR24HPC1Component::loop() {
-  uint8_t byte;
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
 
-  // Is there data on the serial port
-  while (this->available()) {
-    this->read_byte(&byte);
-    this->r24_split_data_frame_(byte);  // split data frame
+    for (size_t i = 0; i < to_read; i++) {
+      this->r24_split_data_frame_(buf[i]);  // split data frame
+    }
   }
 
   if ((this->s_output_info_switch_flag_ == OUTPUT_SWTICH_OFF) &&

esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp

@@ -30,14 +30,21 @@ void MR60BHA2Component::dump_config() {
 
 // main loop
 void MR60BHA2Component::loop() {
-  uint8_t byte;
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
 
-  // Is there data on the serial port
-  while (this->available()) {
-    this->read_byte(&byte);
-    this->rx_message_.push_back(byte);
-    if (!this->validate_message_()) {
-      this->rx_message_.clear();
+    for (size_t i = 0; i < to_read; i++) {
+      this->rx_message_.push_back(buf[i]);
+      if (!this->validate_message_()) {
+        this->rx_message_.clear();
+      }
     }
   }
 }

esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp

@@ -49,12 +49,19 @@ void MR60FDA2Component::setup() {
 
 // main loop
 void MR60FDA2Component::loop() {
-  uint8_t byte;
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
 
-  // Is there data on the serial port
-  while (this->available()) {
-    this->read_byte(&byte);
-    this->split_frame_(byte);  // split data frame
+    for (size_t i = 0; i < to_read; i++) {
+      this->split_frame_(buf[i]);  // split data frame
+    }
   }
 }
 

esphome/components/tuya/tuya.cpp

@@ -31,10 +31,19 @@ void Tuya::setup() {
 }
 
 void Tuya::loop() {
-  while (this->available()) {
-    uint8_t c;
-    this->read_byte(&c);
-    this->handle_char_(c);
+  // Read all available bytes in batches to reduce UART call overhead.
+  int avail = this->available();
+  uint8_t buf[64];
+  while (avail > 0) {
+    size_t to_read = std::min(static_cast<size_t>(avail), sizeof(buf));
+    if (!this->read_array(buf, to_read)) {
+      break;
+    }
+    avail -= to_read;
+
+    for (size_t i = 0; i < to_read; i++) {
+      this->handle_char_(buf[i]);
+    }
   }
   process_command_queue_();
 }