Hmm I just did the same as you did and it works!

Do not overwrite mISDN_core.ko

From: openbsc-bounces@lists.osmocom.org [mailto:openbsc-bounces@lists.osmocom.org] On Behalf Of Lennart Muller
Sent: Sunday, July 31, 2011 4:21 AM
To: openbsc@lists.osmocom.org
Subject: Re: Current OpenBSC + LCR using MNCC socket

2011/7/30 Seungju Kim <admin@manateeshome.com>

Yes, I checked dmesg but all it says is "Unknown symbol flush_work_sync"
there was nothing else.
I DID patch the code, and I tried adding EXPORT_SYMBOL(flush_work_sync); but
it still does not work.

Have you installed all modules using make install?
I copied only the mISDN_l1loop.ko to the kernel module directory, because all other modules are already included in your kernel.
You could try to restore your old kernel modules and copy only the one missing module by hand.

Might somebody be able to test that issue and correct the patch? I'm not that familar with mISDN and kernel modules.
Just tried to make it work quickly, and l1loop works fine so far.

-- Lennart