On 11.10.2013 15:36, Felipe Balbi wrote:
> Hi,
>
> On Fri, Oct 11, 2013 at 10:38:13AM +0200, Sebastian Andrzej Siewior wrote:
>> I have am335x-evm with one port running in OTG mode. Since commit
>> fe4cb09 ("usb: musb: gadget: remove hcd initialization") the loaded
>> gadget does non pop up on the host. All I see is
>> |usb 4-5: new high-speed USB device number 52 using ehci-pci
>> |usb 4-5: device descriptor read/64, error -110
>>
>> Since a later commit 2cc65fe ("usb: musb: add musb_host_setup() and
>> musb_host_cleanup()) the gadget shows up on the host again but only
>> in OTG mode (because we have the host init code running). It does not
>> work in device only mode.
>> If running in OTG mode and the gadget is removed and added back (rmmod
>> followed by modprobe of a gadget) then the same error is pops up on the
>> host side.
>>
>> This patch ensures that the gadget side also executes musb_start() which
>> puts the chip in "connect accept" mode. With this change the device
>> works in OTG & device mode and the gadget can be added & removed
>> multiple times.
>> A device (if musb is in OTG mode acting as a host) is only recognized if
>> it is attached during module load (musb_hdrc module). After the device
>> unplugged and plugged again the host does not recognize it. We get a
>> buch of errors if musb running in OTG mode, attached to a host and no
>> gadget is loaded. Bah.
>> This is one step forward. Host & device only mode should work. I will
>> look at OTG later. I looked at this before commit fe4cb09 and OTG wasn't
>> working there perfectly so I am not sure that it is a regression :)
>>
>> Cc: Daniel Mack <zonque@xxxxxxxxx>
>> Cc: Peter Korsgaard <jacmet@xxxxxxxxxx>
>> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
>
> Is this critical for the -rc or should we add the stable tag here ?
>
People seem to have switched to dual role to work around this bug, so
I'd say it's not critical enough for stable. But it would probably be
good to have it in 3.12.
Daniel
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