From 441ec35d9fd678f482d7c29d42d78dc421e9f6c6 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 7 Feb 2026 00:07:44 +0100
Subject: [PATCH] [seeed_mr24hpc1/mr60fda2/mr60bha2] Batch UART reads to reduce
 per-loop overhead

Replace byte-at-a-time read_byte() calls with batched read_array()
in all three Seeed MR sensor components. Each read_byte() internally
chains through read_array(data, 1) -> check_read_timeout_(1) ->
available(), resulting in ~3 UART driver calls per byte. Batching
into a 64-byte stack buffer reduces this to ~3 calls per loop
iteration regardless of how many bytes are available.
---
 .../seeed_mr24hpc1/seeed_mr24hpc1.cpp         | 19 ++++++++++----
 .../seeed_mr60bha2/seeed_mr60bha2.cpp         | 25 +++++++++++++------
 .../seeed_mr60fda2/seeed_mr60fda2.cpp         | 21 ++++++++++++----
 3 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/esphome/components/seeed_mr24hpc1/seeed_mr24hpc1.cpp b/esphome/components/seeed_mr24hpc1/seeed_mr24hpc1.cpp
index 08d83f9390..949c220c3d 100644
--- a/esphome/components/seeed_mr24hpc1/seeed_mr24hpc1.cpp
+++ b/esphome/components/seeed_mr24hpc1/seeed_mr24hpc1.cpp
@@ -106,12 +106,21 @@ void MR24HPC1Component::update_() {
 
 // main loop
 void MR24HPC1Component::loop() {
-  uint8_t byte;
+  int avail = this->available();
+  if (avail > 0) {
+    // Read all available bytes in batches to reduce UART call overhead.
+    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) &&
diff --git a/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp b/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
index b9ce1f9151..8cbf3e2e29 100644
--- a/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
+++ b/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
@@ -30,14 +30,25 @@ void MR60BHA2Component::dump_config() {
 
 // main loop
 void MR60BHA2Component::loop() {
-  uint8_t byte;
+  int avail = this->available();
+  if (avail == 0) {
+    return;
+  }
 
-  // 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();
+  // Read all available bytes in batches to reduce UART call overhead.
+  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->rx_message_.push_back(buf[i]);
+      if (!this->validate_message_()) {
+        this->rx_message_.clear();
+      }
     }
   }
 }
diff --git a/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp b/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
index b5b5b4d05a..259e60119d 100644
--- a/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
+++ b/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
@@ -49,12 +49,23 @@ void MR60FDA2Component::setup() {
 
 // main loop
 void MR60FDA2Component::loop() {
-  uint8_t byte;
+  int avail = this->available();
+  if (avail == 0) {
+    return;
+  }
 
-  // Is there data on the serial port
-  while (this->available()) {
-    this->read_byte(&byte);
-    this->split_frame_(byte);  // split data frame
+  // Read all available bytes in batches to reduce UART call overhead.
+  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->split_frame_(buf[i]);  // split data frame
+    }
   }
 }