Re: USB_MUSB_DA8XX with g_multi.ko

From: Jon Ringle
Date: Wed Jun 25 2014 - 22:46:12 EST


On Wed, Jun 25, 2014 at 11:52 AM, Jon Ringle <jon@xxxxxxxxxx> wrote:
> On Wed, Jun 25, 2014 at 11:35 AM, Andrzej Pietrasiewicz
> <andrzej.p@xxxxxxxxxxx> wrote:
>> W dniu 25.06.2014 17:13, Jon Ringle pisze:
>>
>>> In commit 787f5627bec80094db487bfcb401e9744f181aed
>>> usb: musb: make davinci and da8xx glues depend on BROKEN
>>>
>>> USB_MUSB_DA8XX was marked as BROKEN
>>>
>>> A few months ago, we updated the linux kernel on our AM1808 SoC based
>>> embedded board from Linux 2.6.33 to the latest long term 3.12.
>>>
>>> I am interested in having the USB gadget support on my board, so I
>>> removed BROKEN on USB_MUSB_DA8XX. I found that when I modprobe
>>> g_ether, g_serial, and g_mass_storage (by themselves), they all appear
>>> to work as expected, but if I try to use g_multi to have a composite
>>> device supporting all three simultaneously, I run into failure during
>>> initialization.
>>>
>>
>> <snip>
>>
>>
>>>
>>>> From this I can see that it's failing on the following call in
>>>> fsg_bind():
>>>
>>> ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
>>>
>>
>> Just a random guess (I don't know your hardware): how many bulk,
>> iso and interrupt endpoints does your hardware provide? Perhaps you
>> just run out of endpoints?
>
> Perhaps... From the documentation it appears that I can have 4
> simultaneous RX/TX endpoints... Is this not enough?

I now see that each function seems to require 2 endpoints, so with 4
endpoints available, I can only have two functions with this hardware.
I tested this successfully with g_adm_ms.ko having both serial and
mass storage working. The only thing I needed to do was to remove the
BROKEN dependency on USB_MUSB_DA8XX. Is there anything else I would
have to do besides just removing BROKEN to get this accepted back into
the kernel source tree?

Jon
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