Re: Gadget regression with enabling of MUSB babble interrupt handling

[Daniel Mack <daniel@zonque.org>]

Hi Tony,

On 06/19/2014 12:31 PM, Tony Lindgren wrote:
> * Daniel Mack <daniel@zonque.org> [140619 03:10]:
>> On 06/19/2014 11:56 AM, Tony Lindgren wrote:
>>> Looks like commit ca88fc2ef0d7 (usb: musb: add a work_struct
>>> to recover from babble errors) causes MUSB gadgets to stop
>>> enumerating at least on omap3. Reverting the the commit fixes
>>> the issue.
>>
>> Hmm, so do you see babble errors occuring?
> 
> Not that I noticed of.
>  
>> Also, there are some more patches for musb and babble error recovery on
>> the usb list, namely the ones starting here in v6:
>>
>>   http://marc.info/?l=linux-usb&m=140109627505065&w=4
>>
>> Care to give them a try?
> 
> I can confirm that "[PATCH v6 1/5] usb: musb: core: Handle Babble
> condition only in HOST mode" fixes the issue for me. Also the
> explanation in the patch description explains why it breaks, and
> probably for all gadgets too because "BABBLE and RESET share the
> same interrupt" so it's RESET in peripheral mode.

Ok, thanks for testing. I was told Felipe was out for some weeks, so I
don't know when these patches will be reviewed and merged.

> But that also raises a question: Were these patches merged for
> v3.16 ever even tested in peripheral mode?

At the time, I had no such hardware to test this on, so I was hoping for
more testers to give them a try in different environments, which
apparently didn't happen. It fixed a dead USB port condition on
host-mode enabled hardware, though.

We should make sure at least patch 1/5 from the series mentioned above
makes it to 3.16.


Thanks,
Daniel