GPIO Driver/SysFS problem with Linux 3.16

Good morning,

We are facing a problem using Altera GPIO driver & SysFS on our system.

Our design include:

- A Nios2 processor running rel_socfpga-3.16_14.09.02 Linux version.

- 1 Altera pio IP who handle 8 inputs

- 1 Altera pio IP who handle 8 outputs

- 1 Altera pio IP who handle 8 bidirectionnals signals

We can export using SysFS all I/O off the design and drive out every output signal.

However, we are able to read only one of the 8 input values.

Same phenomenon for bidirectionnal signal after setting theire direction to input.

Input values are always seen as '1'.

For example:

8 bidir set as input are exported from gpio248 to gpio255.

All of them are connected to GND.

Only gpio255 value is correct ( value = 0)

The others values stay at 1.

Does anyone knows this problem and a solution?

Regards,