Straight to the point. My wifi has not been working properly since after a few days after upgrading its firmware and android version.

Issue description

The issue is rather inconsistent. Wifi will usually not detect any networks. Sometimes it will spend around 30 seconds scanning, and then it will show available networks for around 10 seconds, after which the networks disappear from the list. Trying to connect in this span of time does nothing, that is, when I tap on the network and then choose "connect", I get bumped back on the network list as if nothing had happened. Other times, attempting to connect a network makes all networks disappear instantly. In this case, the networks come back after a few seconds, and the network I was trying to connect to appears as "connecting", but all networks disappear shortly after this. Occasionally, wifi will get stuck while turning on, but this usually happens after/while I'm tinkering permissions.

I must remark, this happens on every network, it is not a router-related issue. I also ruled out a hardware issue, since I am able to briefly detect networks, but I am not able to connect to them.

Origin of the issue

The issue started after a few days after I updated my tablet's ROM, using the official software released by the developer, and after rooting the tablet. The odd thing is that the wifi worked just fine for a few days after I upgraded the software. While this could be the origin of this problem, it could come from a different source. By all means do read the "Other (weird) information"

Fixes I have tried

  • Changing wifi settings (changing advance settings, changing device name in wifi direct's settings, etc.)
  • Factory reset (issue persisted even before I rooted the device again)
  • Editing permissions of every file inside the dhcpcd folder, using the app X-plore (with root permission), as well as other files inside the "permission" folder (all the ones that have the "wifi" name on them).
  • Various "Wifi fixer" apps.
  • MAC changer apps (to change my MAC address)
  • Wiping cache partition

Fixes I have not tried

  • Installing another ROM (I am unable to do that, because there are no other ROMs compatible for my device, not even custom ones)
  • Rolling back my android version (from 4.4.2 to 4.2)

Other (weird) information

  • Mac Address oddities

My MAC address changed after a few days, just when the issue begun. I am not sure if this is related, but I'll explain it anyway: My girlfriend's ISP is a local small company (owned by 1-3 people) which requires you to send them your MAC address so they can... whitelist your device? If you do not send them your MAC address, you can connect to the network, but with limited access (only their webpage). This seems odd to me because the network itself is private (that is, it has its own password, like any private network) but you are still required to send the MAC address of every device you want to connect to your network.

When I went to her house and I tried to connect after I had upgraded my ROM, I got limited access, despite having already sent my tablet's MAC address many months ago. I checked my MAC address and I noticed it had changed to 00:90:4c:07:71:12. I messaged the ISP guy and sent him my new MAC. But I checked again, after a few minutes and my MAC was back to its old number. The MAC went back and forth from the new one to the old one a few times, and it finally stuck with the new one. The ISP "guy" said he would try to "remote access" to try and fix the issue (that is, my limited access to my GF's particular network).

After that, my tablet couldn't connect to any network, and the issue begun as I described above. I thought this unrelated to the issue, but I found some threads complaining about issues related to MACs that begin with 00:90:4c. Could this be the source of the problem?

  • Brief but stable conection

Last week, my tablet was able to connect normally to my university's network. It happened after I enabled the "mobile network" settings (Data enabled, Data roaming). I have no data service on this tablet, despite that, after checking those boxes I was able to connect like the issue had never existed. However, after disconnecting from that network the issue came back as if nothing happened. I have not been able to reproduce this, not by connecting to the same network, not by being in the same spot (so I would have the same wifi signal strength).

  • Wifi was on after factory reset

As it says, after reseting the tablet (and wiping the internal SD card, of course) the wifi was already on by default. Could this mean anything?

Device description and more information

It's an Onda v975s, with android kitkat 4.4.2, Firmware version v4.4_V1. Kernel version 3.3.0. Please, do ask for more information if needed.

I also have some logcats that point at wpa_supplicant.

wpa_supplicant: Could not set interface wlan0 flags (UP): Operation not permitted

You can find the full logcat here on Pastebin.

If you made it through this long post, I thank you. I just ran out of ideas, so I hope someone here is able to help me.

  • 4
    excellent question, very detailed, +1 from me. Can you add the logcat to Github Gist or pastebin? Including it here will make the quesion even longer IMO.
    – benjamin
    Commented Oct 28, 2015 at 14:05
  • I also thought it would make the question too long. I uploaded the .txt contents: pastebin.com/C2Lfyy7T Thanks for your time Commented Oct 28, 2015 at 14:13
  • 2
    +1 from me, too. Have you records of your "original MAC address"? The first 3 pairs at least? 00:90:4c is used by epigram, inc. If your new address points to a different company, that would be very strange (usually, a MAC address doesn't change – which is why it's used for network protection by MAC filters, to answer that part of your question). I had a comparable issue once, and it was related to incompatibilities of the newer ROM with the radio image of the phone, but no MAC change then.
    – Izzy
    Commented Oct 28, 2015 at 14:39
  • Epigram... that's even odder, since I'm from Spain. How could that MAC change happen? As for logs from before the ROM update, I unfortunately have none. What did you do to fix your issue? Do you think it could help my case? Commented Oct 28, 2015 at 20:18
  • More logs please, these logs will give a more detailed story of what issues your wifi is having. Radio log: adb logcat -b radio -v time -d > logcat_radio.log wifistate errors - fatals: adb logcat WifiStateMachine:E *:S -v long > wifi.txt Kernel log: adb shell su -c dmesg > dmesg.txt
    – Bo Lawson
    Commented Dec 17, 2015 at 9:19

2 Answers 2


By looking at these two lines in logcat:

Could not set interface wlan0 flags (UP): Operation not permitted

WifiStateMachine: Driver start failed, retrying

I would say that the 4.4.2 ROM has a faulty/missing WiFi card driver (2nd line) without which you of course can't even start/scan/keep the WiFi connection (1st line).

As you have said, you haven't tried flashing it back to 4.2, but I strongly recommend to do so, at least to check if then the WiFi would work again.

If it then does work, that means the 4.4.2 ROM probably has faulty drivers or the permissions somehow changed so you don't have permission to turn WiFi on.

Depending on the outcome, you can either:

  • Try to contact your OEM for a fix in 4.4.2
  • Stay on 4.2 since you got no custom ROMs available
  • MAYBE try to transfer drivers somehow from 4.2 into 4.4.2

I wouldn't rely much on the last option because of compatibility and changes in Android between versions, and besides that, it would require a lot of technical skill and knowledge + it could lead to potential hardware damage.

  • Yes, rolling back to 4.2 does fix the issue. The OEM has released no fix, and contacting them only got me the "Soon TM" kind of answer. So I'm probably stuck with the 4.2 ROM... which also has some issues on its own. Moral of the story, do not buy cheap tablets from crappy chinese companies. Commented Dec 18, 2015 at 12:57
  • Sorry for doubleposting. I am wondering... If there was a custom ROM for my device that featured those missing drivers (+ others I also need and are lacking) my problems would be solved. Of course there aren't any custom roms for my tablet model. But what IF I made that ROM myself? I suppose even considering this may be silly, since I have zero programming knowledge... but could I make a small "edit" to a preexisting compatible stock ROM to add those drivers/features that I want? It's not a complete makeover, but rather a small addition. Is that a task too big for a rookie like me? Commented Dec 18, 2015 at 18:00
  • Unfortunately I cant help u more in that manner because here things go to hardware level, which I am not very familiar with...
    – Chapz
    Commented Dec 24, 2015 at 12:03

It seems that your EFS ( encrypting file system ) got corrupted. I can't tell why. But I have found to fix it. You can check these links -->

  1. XDA
  2. A blog
  • 1
    Could you also quote the content (like, how-to steps) from the article to preserve the content if the link is dead later?
    – Manu
    Commented Dec 20, 2015 at 7:45
  • I believe xda is not going to drop that link ever. Even if so, I can post steps here too. No probs at all.
    – Vivek Ji
    Commented Dec 20, 2015 at 8:35
  • I'm on vacation right now, but I'll try these as soon as I can, and I'll make you know if it works, thanks for the suggestion. Commented Dec 23, 2015 at 14:47

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