[v2] usb: dwc3: Prevent indefinite sleep in _dwc3_set_mode during suspend/resume

[Felipe Balbi <balbi@kernel.org>]

Hi,

Roger Quadros <rogerq@ti.com> writes:

> Hi Felipe,
>
> On 09/03/18 14:47, Roger Quadros wrote:
>> In the following test we get stuck by sleeping forever in _dwc3_set_mode()
>> after which dual-role switching doesn't work.
>> 
>> On dra7-evm's dual-role port,
>> - Load g_zero gadget driver and enumerate to host
>> - suspend to mem
>> - disconnect USB cable to host and connect otg cable with Pen drive in it.
>> - resume system
>> - we sleep indefinitely in _dwc3_set_mode due to.
>>   dwc3_gadget_exit()->usb_del_gadget_udc()->udc_stop()->
>> 	dwc3_gadget_stop()->wait_event_lock_irq()
>> 
>> To fix this instead of waiting indefinitely with wait_event_lock_irq()
>> we use wait_event_interruptible_lock_irq_timeout() and print
>> and error message if there was a timeout.
>> 
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>
> Thanks for picking this for -next.
> Is it better to have this in v4.16-rc fixes?
> and also stable? v4.12+

Well, there was no "Fixes: foobar" or "Cc: stable" lines in the commit
log ;-)

The best we can do now, is wait for -rc1 and manually send the commit to
stable.