[JB] Bug Report: NFC Broken (?)

[Miltos95]

Hello, i've recently updated 2 phones to Jelly Bean (6.2.A.0.400).

The problem is that even if the NFC is enabled, it doesn't detect SmartTags nor the other Xperia P (Android Beam).

Anyone can confirm?

P.S. None of the 2 Xperia Ps can detect each other or the SmartTags. Will try with a Sola on ICS later.

Edit: It doesn't even work with android bean between my Xperia P on JB and a Sola on ICS!

Edit 2: Reverted my Phone to ICS while i left the other one on JB. Android beam works between the Phones now (Xperia P to Xperia P), SmartTags on the JB don't work while on my Xperia P running ICS works. (Both phones have Smart Connect installed and Xperia SmartTags too).

[Miltos95]

What do you mean? It "upgraded" the NFC firmware when i updated to JB.

Edit: Updated again to JB but with a reset. Still, touching phones back to back doesn't work.

[ThorAsgard]

NFC work again in may case : I clear data from smart connect, avant hold down volume+ & power for 5 sec (I waited for the 3 vibrations) for cold restart.

After reboot, NFC was working again !

[dzegarra]

This is not a problem of SmartTags app because even a third app NFC reader not detect anything. I have two Xperia tags and some other devices with NFC chips. None of then dispatch data to the reader, so, this is a problem of kernel or the update script. Maybe if I restore to factory start working again.

[AxxO89]

Did you try what ThorAsgard said? clear data/updates from smart connect, uninstall SmartTags, reboot.

My NFC works with an NFC app now.

[dzegarra]

Well. I don't think the smarttag was the problem. But only for try all the options I do what ThorAsgard said.

The same result, the NFC reader still not respond.

I not root my cell so I can't ejecute dmesg and see if the hardware is listed by the kernel.

[ThorAsgard]

Even a reboot with volume+ & power doesn't fixed your problem ? have you waited the 3 or 4 quick vibrations of the phone ? (and not only 1 vib on reboot)

[dzegarra]

Yes, even after the cold reboot (the three vibs and all that). The reader is death.

Well, I thing is a problem of the update script. I don't think the kernel is broken ( will be very embarrassing launch a kernel with a bug so obvious ).

Do a factory reset will be the real solution but, first I need root my phone and backup some apps than only save data in the device (I cannot use Titanium Backup if the phone is not rooted).

[Miltos95]

You're wasting your time, i already did a factory reset (been playing with flashtool too much lately). It just doesn't work! But here's the odd thing.

Firstly i updated mine and my brother's phone to Jelly Bean. No wipe or factory reset. Tried smarttags and touching both phones back to back to transmit content - no luck. Both NFCs seemed dead. No phone was initiating a connection, they weren't even making the sound when you touch the phones back to back. I wiped my phone completelly too, still no luck.

Second, i downgraded my phone to ICS (i left my brother's running Jelly Bean). My phone running ICS was able to detect smarttags AND was able to communicate with every phone by touching back to back (yes, it was able to communicate with my brother's too, running jelly bean).

Odd. Seems like the NFC doesn't scan on Jelly Bean but if it gets a "pulse" then it does reply to the request and seems like it does actually work? I'm not a developer and i might say s#$t right now but that's how i think of it.

You can try it on your own (the factory reset) but don't expect much. At least for me it didn't work.

[dzegarra]

I don't know exactly how the nfc works. I know that the simple rf chips can be readed and even updated but only that. And what the phone has is a rf reader not a writer.

This is how I think Nfc works:

Each phone has a rf chip and a reader. In the rf chip (a dummy read only chip) is written the config of a bluetooth door to the phone so, when other phone reads this config is capable to send data via bluetooth to the other device using this config previously reserved is the phone.

So, when your phone with ICS read the rf chip of the JB phone, the JB phone doesn't know that. Normally a rf chip is powered by a small magnetic field created by the reader. Even is posible to the rf chip is receiving power but the kernel doesn't detected.

To know the truth you have to execute the dress command and see if the nfc hardware is present.

You have a good opportunity because can compare the results of

I don't know exactly how the nfc works. I know that the simple rf chips can be readed and even updated but only that. And what the phone has is a rf reader not a writer.

This is how I think Nfc works:

Each phone has a rf chip and a reader. In the rf chip (a dummy read only chip) is written the config of a bluetooth door to the phone so, when other phone reads this config is capable to send data via bluetooth to the other device using this config previously reserved is the phone.

So, when your phone with ICS read the rf chip of the JB phone, the JB phone doesn't know that. Normally a rf chip is powered by a small magnetic field created by the reader. Even is posible to the rf chip is receiving power but the kernel doesn't detected.

To know the truth you have to execute the dmesg command and compare the results of the phone with JB and the phone with ICS.

After you tell me that even with a factory the reader doesn't work I letting to think is a kernel problem. That will be very stupid from Sony.

Oh, a mode of experiment, can you test if you can read the JB phone tag when it is off?

[xtraJosh]

there is already a solution for this mentioned in the other thread. mine works like ICS now. there is a search bar above. use it.