[Important] Fixed a Wi-Fi connect issue of ESP8266 softAP (GIT8266O-534)

[donghengqaz]

[Important] Fixed a Wi-Fi connect issue of ESP8266 softAP

Issue Summary:

If system powers off or restarts during ESP8266 softAP‘s first initialization, there is a small probability that other stations cannot connect to ESP8266 softAP after system restarts.

Root Cause:

If an unexpected system restart or shutdown interrupted ESP8266 saving PMK (Pairwise Master Key) to SPI Flash during ESP8266 softAP’s first initialization, then after ESP8266 restarts, other devices may fail to connect to ESP8266 softAP since there is no valid PMK for Wi-Fi connection.

Solution:

Update ESP8266 SDK to check whether the PMK is correct when reads it from SPI flash, and if the PMK is wrong, then the SDK will recalculate a new and correct PMK and save it into SPI flash.

We have fixed this issue in each release version branches:

• release/v3.3 branch: commit 210943a
• release/v3.2 branch: commit 6a021d6
• release/v3.1 branch: commit 8f17a7c
• release/v3.0 branch: commit da8a684

It is suggested that customers who used ESP8266 softAP function can update ESP8266 RTOS SDK to solve this issue. And since we keep updating release branches with bug fixes, it is highly recommended that users can update to the latest commit of each release branch.

---

[重要] SoftAP 无法连接问题

现象:

当 ESP8266 第一次初始化为 softAP 的过程中，系统关机或者重启，有小概率导致重启以后其他设备无法连接到 ESP8266 softAP。

问题原因:

在 ESP8266 第一次初始化为 softAP 的过程中，如果恰好在存储 PMK (Pairwise Master Key) 时突然关闭电源或重启，可能导致 PMK 没有正确存储到 SPI Flash。这种情况下，当 ESP8266 重新启动后，初始化 softAP 加载了错误的 PMK，导致其他设备无法连接到 ESP8266 softAP。

解决方案:

ESP8266 SDK 增加了针对从 SPI Flash 读取的 PMK 进行检查，以确保加载的 PMK 的正确性；如果检查发现 PMK 错误，则重新计算 PMK 并更新存储到 SPI Flash。

当前问题的 bugfix 已经同步到各个版本的 release 分支上，请使用了 ESP8266 softAP 功能的客户注意更新，各个版本的具体 commit ID 如下：

• release/v3.3 branch: commit 210943a
• release/v3.2 branch: commit 6a021d6
• release/v3.1 branch: commit 8f17a7c
• release/v3.0 branch: commit da8a684

由于我们会在各个 release 分支修复客户反馈的使用问题，[强烈建议]客户关注并更新到对应版本的最新 commit。