USB OTG doesn't work on beagle board if HUB is used with two different device classes are attached to it


We are using Beagle board rev.B4. As beagle board doesn't have
ethernet support, we are using 'AIRKLINK101'-USB to Ethernet adapter.
Its driver is already present in kernel. We also want to use USB
pendrive simultaneously. So we use HUB to which both the devices are
connected. HUB and Beagle board are self powered, and HUB is connected
to USB OTG connector of beagle board. This is our setup.


1. Bring up the ethernet interface, and mount NFS file system.
2. Mount USB pendrive in FS (into ramdisk directory)
3. Mount MMC card (into ramdisk directory)
4. Once all are mounted (in any sequence), if I try to copy from any
mounted directory to the other. Kernel crashes.
5. If only pendrive or ethernet adapter is used, sytem works fine
without crash.
6. Sometimes kernel crashes while mounting pendrive or NFS itself.
7. Similar issue is not there on OMAP3 OSK board (EVM).


1. Is there any issue with Beagle board to work with two different USB
devices connected to it (through HUB)?
2. I compared USB driver codes of both the Beagle board and OMAP3 OSK
board. There are differences in files present in '/usb/musb' folder.
Can I try replacing those files directly from OSK linux USB driver? or
any more changes are required? Will it cause any other issues?
3. Has anybody faced similar issue? If anyone has some pointer
regarding this, please let me know.

I am attaching kernel log along with this post.


Can somebody please answer this? I will be having a similar issue with
my project (waiting on board to get here).

Satyajit, can you please post solution if you find one?

This is the multiplexing bug in MUSB. There are patches available on
the linux-omap mailing list but they haven't been integrated into
Angstrom yet.

Here is the patch:

If you don't build your own kernel, Koen regularly posts new kernels
that have these (and other) fixes. This is his latest kernel:

These are the latest modules I could find:

I'm running the multiplexing patch and I'm able to use USB drive and
ethernet simultaneously.

- Nathan

Thank you Nathan.
I applied the patch. Now USB is working with ethernet adapter and USB stick simultaneously.