Serial ports on ICS

```
Hello,
I have android 2.3 from TI site and now on second sd card I put rowboat ICS
version. On my 2.3 I'm able to run pppd via /dev/ttyS2 port.

But on ICS log cat show me 'Couldn't get channel number: I/O error'.

#setserial -G /dev/ttyS2
/dev/ttyS2 uart unknown port 0x0000 irq 0 bound_base 0 spd_normal

When I run setserial on 2.3, I see proper values of UART and IRQ.

There is any way to enable serial ports in ICS?
```

Original issue reported on code.google.com by `styczyns...@gmail.com` on 7 Feb 2012 at 4:42

Start by comparing the Android 2.3 and ICS serial-port behavior around /dev/ttyS2, using logcat, setserial, and pppd as the reported entry points. Confirm whether ICS exposes the UART and its IRQ, and consider the issue done when setserial reports valid values and pppd can use /dev/ttyS2 as before.

Written by the indexing model from the issue text.