From 4db5835b6ffd5d7460e6d53ec55ab3ad8c9ec0cd Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Mon, 9 Feb 2026 09:32:08 -0600
Subject: [PATCH] Update comment explaining early guard

---
 esphome/components/cse7766/cse7766.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/esphome/components/cse7766/cse7766.cpp b/esphome/components/cse7766/cse7766.cpp
index b4b282dff97..c68c348be0d 100644
--- a/esphome/components/cse7766/cse7766.cpp
+++ b/esphome/components/cse7766/cse7766.cpp
@@ -15,8 +15,9 @@ void CSE7766Component::loop() {
     this->raw_data_index_ = 0;
   }
 
-  // All current UART available() implementations return >= 0,
-  // use <= 0 to future-proof against any that may return negative on error.
+  // Early return avoids stack adjustment for the batch buffer below
+  // and prevents updating last_transmission_ when no data is available.
+  // loop() runs ~7000/min so most calls have nothing to read.
   int avail = this->available();
   if (avail <= 0) {
     return;