PSA: Fake registration on 5.12.1, no Wi-Fi can drain battery in particular condition

[WaseemAlkurdi]

I've recently noticed that on my KT2, the battery goes down very rapidly ... something like 20% per hour of reading.
At first, I ignored it, thinking that I have tough luck with batteries on used Kindles ...
But it became so severe that I decided to check whether it was after all a software issue.

First, I booted into diags and chose the Gas Gauge option. Strangely, the battery discharged very slowly.

Then, I booted into main and ran top. A process running as the framework user was eating up to 90% CPU. Even weirder.

Stumped, I checked dmesg for anything that may be odd. Nothing at all.

This left me with one choice before giving up: the /var/log/* directory, where the framework stores its logs.

Viewing the log at /var/log/messages gave me a very unpleasant surprise: Something was being executed over and over and again (and failing) every few seconds:

[...]
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Init Commiting datset 
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:WhisperSyncV2INFO: Module = DataSetSync :Apps:Device:SettingsDeviceSettings
190924:221232 cvm[4409]: E WhisperSyncV2HttpClient:Error:: Exception while ensuring wifi connection - Could not connect to wireless
190924:221232 cvm[4409]: E WhisperSyncV2PaginateServiceImpl:failure=GetConnectionFailed:reason=getting connection failed while creating a dataset:
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information::datset changes upload DeviceSettings
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Deleting pending datasets 
190924:221232 cvm[4409]: I AbstractSyncController:Information:: Dataset uploading fail for empty updates link DeviceSettings
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Firing nonpaginateclients  datset sync completed event
190924:221232 cvm[4409]: E WhisperSyncV2HttpClient:Error:: Exception while ensuring wifi connection - Could not connect to wireless
190924:221232 cvm[4409]: E WhisperSyncV2PaginateServiceImpl:failure=GetConnectionFailed:reason=getting connection failed while creating a dataset:
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Init Commiting datset 
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:WhisperSyncV2INFO: Module = DataSetSync :Apps:Device:SettingsDeviceSettings
190924:221232 cvm[4409]: E WhisperSyncV2HttpClient:Error:: Exception while ensuring wifi connection - Could not connect to wireless
190924:221232 cvm[4409]: E WhisperSyncV2PaginateServiceImpl:failure=GetConnectionFailed:reason=getting connection failed while creating a dataset:
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information::datset changes upload DeviceSettings
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Deleting pending datasets 
190924:221232 cvm[4409]: I AbstractSyncController:Information:: Dataset uploading fail for empty updates link DeviceSettings
190924:221232 cvm[4409]: I WhisperSyncV2PaginateServiceImpl:Information:: Firing nonpaginateclients  datset sync completed event
190924:221232 cvm[4409]: E WhisperSyncV2HttpClient:Error:: Exception while ensuring wifi connection - Could not connect to wireless
190924:221232 cvm[4409]: E WhisperSyncV2PaginateServiceImpl:failure=GetConnectionFailed:reason=getting connection failed while creating a dataset:
[...]

So, I decided to unregister the Kindle by removing the file at /var/local/java/prefs/reginfo and rebooting.
And after rebooting, the difference was night and day. It's actually back to advertised Kindle levels!
CPU usage now never exceeds 5%, and all is fine!

[S]After reading through the log that I have, it seems that the issue is caused by something related to Settings -> Device Options. I do distinctly remember having tried to rename the Kindle using the Device Name option in Settings -> Device Options. It told me that I'm not connected to Wi-Fi, which I then ignored ... and it seems to have bitten me back now.[/s] See edit.

Note that my fake registration was done when the Kindle was on firmware 5.9.4. I gave it an OTA update to 5.12.1 yesterday, and today, I have deleted the fake registration info to fix that issue as stated above.

Trying to re-register it again using that hack no longer works. It would throw you to the setup screen (which you can skip) and ignore the whole fake reginfo file and all my existing items except KUAL won't open.

Edit: I've done a factory reset, installed the hotfix, and placed the fake registration file again in its location. It worked, and files do open, but the CPU usage spike happens again. I did not touch anything or install any mods after the factory reset apart from the hotfix.
As before, removing the fake registration fixes the issue.

[mireq]

Hello,
i had the same problem. Fix was pretty simple with this commands:

stop framework
echo "nodb" > /var/local/wsync.db
chattr +i /var/local/wsync.db
start framework

Explanation:

Service WhisperSyncV2PaginateServiceImpl is started from /opt/amazon/ebook/lib/kaf.jar. Decompiled source code looks like this

protected boolean openDb() {
  LOG.info(" Init Sanity of resources ");
  if (!this.checkIntegrity()) {
    LOG.a(lCJ, new String[] { "Pragma integrity check failed" }, null);
    DeviceMetricLogger.a("WhisperSyncV2PaginateService", "Sanity", "CorruptDB", 1, null, 0, 0);
    reinitDb();
    return dbOpened();
  }
  return true;
}

protected boolean reinitDb() {
  LOG.info(" Init Clear resources ");
  File file = new File("/var/local/wsync.db");
  if (file.exists()) {
    if (!file.delete()) {
      LOG.error("delete Database Failed");
      DeviceMetricLogger.a("WhisperSyncV2PaginateService", "clearResource", "clearFailed", 1, null, 0, 0);
      return false;
    }
  }
  return true
}

If corrupted file exists, it's removed and created new. If cannot be removed, then sync service don't start. Simple solution is corrupt file by writing anything, which SQLite don't parse and change it to protected.