From d2a1f7ee31ea1f51768ea02bd91e573ac0ff1b48 Mon Sep 17 00:00:00 2001
From: rwrozelle <rwrozelle@gmail.com>
Date: Fri, 16 Oct 2026 23:02:54 -0400
Subject: [PATCH] [zephyr] Fix preference log levels and report settings
 read/save errors (#20810)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: J. Nick Koston <nick@koston.org>
---
 esphome/components/zephyr/preferences.cpp | 29 ++++++++++++++++++-----
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/esphome/components/zephyr/preferences.cpp b/esphome/components/zephyr/preferences.cpp
index 6be5f1ce4a5..d5522da03aa 100644
--- a/esphome/components/zephyr/preferences.cpp
+++ b/esphome/components/zephyr/preferences.cpp
@@ -5,6 +5,7 @@
 #include "preferences.h"
 #include "esphome/core/log.h"
 #include <zephyr/settings/settings.h>
+#include <sys/types.h>
 #include <cinttypes>
 #include <cstring>
 
@@ -23,7 +24,11 @@ bool ZephyrPreferenceBackend::load(uint8_t *data, size_t len) {
   if (len != this->data.size()) {
     char key_buf[KEY_BUFFER_SIZE];
     this->format_key(key_buf, sizeof(key_buf));
-    ESP_LOGE(TAG, "size of setting key %s changed, from: %zu, to: %zu", key_buf, this->data.size(), len);
+    if (this->data.empty()) {
+      ESP_LOGV(TAG, "setting key %s not found", key_buf);
+    } else {
+      ESP_LOGE(TAG, "size of setting key %s changed, from: %zu, to: %zu", key_buf, this->data.size(), len);
+    }
     return false;
   }
   std::memcpy(data, this->data.data(), len);
@@ -87,7 +92,7 @@ bool ZephyrPreferences::load_from_key(uint32_t type, uint8_t *data, size_t len)
 }
 
 bool ZephyrPreferences::sync() {
-  ESP_LOGD(TAG, "Save settings");
+  ESP_LOGV(TAG, "Save settings");
   int err = settings_save();
   if (err) {
     ESP_LOGE(TAG, "Cannot save settings, err: %d", err);
@@ -117,22 +122,34 @@ int ZephyrPreferences::load_setting(const char *name, size_t len, settings_read_
     return 1;
   }
   std::vector<uint8_t> data(len);
-  int err = read_cb(cb_arg, data.data(), len);
+  ssize_t read_len = read_cb(cb_arg, data.data(), len);
+  if (read_len != static_cast<ssize_t>(len)) {
+    ESP_LOGE(TAG, "Cannot read setting %s, got %d of %zu", name, static_cast<int>(read_len), len);
+    return 0;
+  }
 
-  ESP_LOGD(TAG, "load setting, name: %s(%" PRIu32 "), len %zu, err %d", name, *type, len, err);
+  ESP_LOGD(TAG, "load setting, name: %s(%" PRIu32 "), len %zu", name, *type, len);
   auto *pref = new ZephyrPreferenceBackend(*type, std::move(data));  // NOLINT(cppcoreguidelines-owning-memory)
   get_preferences()->backends_.push_back(pref);
   return 0;
 }
 
 int ZephyrPreferences::export_settings(int (*cb)(const char *name, const void *value, size_t val_len)) {
+  int first_err = 0;
   for (auto *backend : get_preferences()->backends_) {
     char name[KEY_BUFFER_SIZE];
     backend->format_key(name, sizeof(name));
     int err = cb(name, backend->data.data(), backend->data.size());
-    ESP_LOGD(TAG, "save in flash, name %s, len %zu, err %d", name, backend->data.size(), err);
+    if (err) {
+      ESP_LOGE(TAG, "Cannot save setting %s, err %d", name, err);
+      if (first_err == 0) {
+        first_err = err;
+      }
+      continue;
+    }
+    ESP_LOGV(TAG, "save in flash, name %s, len %zu", name, backend->data.size());
   }
-  return 0;
+  return first_err;
 }
 
 static ZephyrPreferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)