From 78f98fa08fbbf8f64c5ca72cafb916298c93d20a Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sun, 8 Feb 2026 02:51:27 -0600
Subject: [PATCH] [hlk_fm22x] Drain exact frame bytes on oversize response

Discard exactly length+1 (payload + checksum) instead of flushing
the entire RX buffer, which could eat bytes from the next frame.
---
 esphome/components/hlk_fm22x/hlk_fm22x.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/esphome/components/hlk_fm22x/hlk_fm22x.cpp b/esphome/components/hlk_fm22x/hlk_fm22x.cpp
index 8a12c5e772..fb79113181 100644
--- a/esphome/components/hlk_fm22x/hlk_fm22x.cpp
+++ b/esphome/components/hlk_fm22x/hlk_fm22x.cpp
@@ -135,7 +135,8 @@ void HlkFm22xComponent::recv_command_() {
 
   if (length > HLK_FM22X_MAX_RESPONSE_SIZE) {
     ESP_LOGE(TAG, "Response too large: %u bytes", length);
-    while (this->available())
+    // Discard exactly the remaining payload and checksum for this frame
+    for (uint16_t i = 0; i < length + 1 && this->available(); ++i)
       this->read();
     return;
   }