Hi Sylvain, thanks for that, already getting somewhere. Here are last several lines from strace output:

open("/dev/ttyUSB0", O_RDWR|O_NOCTTY) = 3
14:21:07.712932 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 opost isig icanon echo ...}) = 0
14:21:07.713657 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 opost isig icanon echo ...}) = 0
14:21:07.713847 ioctl(3, SNDCTL_TMR_START or TCSETS, {B115200 -opost -isig -icanon -echo ...}) = 0
14:21:07.715039 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 -opost -isig -icanon -echo ...}) = 0
14:21:07.715261 ioctl(3, TIOCMBIS, [TIOCM_DTR|TIOCM_RTS]) = -1 EPIPE (Broken pipe)
14:21:07.717054 close(3) = 0
14:21:07.720986 write(2, "Cannot open serial device /dev/t"..., 39Cannot open serial device /dev/ttyUSB0

I got -1 at ioctl(3, TIOCMBIS, [TIOCM_DTR|TIOCM_RTS]) (Broken pipe). But it was actually able to open "/dev/ttyUSB0" (returned 3). Have to find out what -1 means at this point.

> Date: Tue, 11 Jun 2013 11:21:23 +0200
> Subject: Re: Cannot open serial device /dev/ttyUSB0
> From: 246tnt@gmail.com
> To: gandguladze@hotmail.com
> CC: baseband-devel@lists.osmocom.org
>
> On Tue, Jun 11, 2013 at 10:44 AM, George Andguladze
> <gandguladze@hotmail.com> wrote:
> > I can read/write baud rates to EEPROM of the device using cp210x-program.
> > Basically I have tried everything apart from reinstalling the OS (Ubuntu
> > 10.04). What might be the issue? (for more info refer to the older
> > conversations)
>
> Try to strace it.
>
> strace osmocon ....
>
>
> Cheers,
>
> Sylvain
>