wait_even_interruptible_timeout(), signal, spin_lock() = system hang

[Shirish Pargaonkar <shirishpargaonkar@gmail.com>]

After this sequence of calls, system hangs (smp, x86 box based with
.34 kernel), can ping only.
I have not been able to break in with Alt Sysrq t, working on that

        rc = wait_event_interruptible_timeout(ses->server->response_q,
                        (midQ->midState != MID_REQUEST_SUBMITTED), timeout);
        if (rc < 0) {
                cFYI(1, ("command 0x%x interrupted", midQ->command));
                return -1;
        }

and when function that invoking function after coming out with ERESTARTSYS
(I kill the command with Ctrl C) calls
 spin_lock(&GlobalMid_Lock);

system hangs.  If I sleep before return -1 (e.g. msleep(1), no hang)

I do not have to use wait_event_interruptible_timeout and no such problems with
wait_event_timeout, it is only when signal/interrupt is involved, I
run into this problem

Any pointers/ideas what could be happening, would be really really appreciated.

Regards,

Shirish