iOS 7.1 update breaks External Accesory inputStream UART read ability

Question

We have MFI approved accessory device. Our protocol assumes continuous readings from accessory in UART mode. It was working perfect before iOS 7.1, but after testing on the iOS 7.1 it is not working properly.

In ATS test suite log we can see success eap records and some AccessoryDataTransfer acked by iPhone.

We can reproduce problem using EADemo. EADSessionController stops read data after some show/close cycles.

Only killing EADemo and relaunch allows us read some data.

Configuration:
iPhone 4 and newer (iOS 7.0), any iPod (iOS 6.x) - OK
iPhone 4s, iPhone 5 (iOS7.1) - Failed

What happens with EA framework in iOS 7.1?

Answer 1

Apple just released update 7.1.2 claiming they solved the issue.

"• Fixes a bug with data transfer for some 3rd party accessories, including bar code scanners"*