Comment 18 for bug 812132

On 10/25/2011 07:43 PM, Oliver Neukum wrote:
> Am Dienstag, 25. Oktober 2011, 13:20:13 schrieb Jesse Sung:
>> On 10/25/2011 04:40 PM, Oliver Neukum wrote:
>>> Am Dienstag, 25. Oktober 2011, 10:37:38 schrieb Jesse Sung:
>>>>
>>>> On some machines, it seems that usb hubs do not get power while
>>>> being suspended. We can get something like this in dmesg:
>>>> usb usb2: root hub lost power or was reset
>>>>
>>>> When this is the case, .reset_resume is called instead of .resume.
>>>> If .reset_resume is not set, bluetooth modules would stay in an unusable
>>>> state because the resume function is not called.
>>>
>>> Have you experimentally verified that? This state of affairs is years
>>> old and should result in a virtual unplug/replug cycle. What are you
>>> seeing?
>>
>> Hi Oliver,
>>
>> Humm... You're right, there is an unplug-replug cycle, but bluetooth
>> doesn't work until I restart bluetoothd. If the resume function is
>> called through .reset_resume, then bluetooth works right after resume.
>
> Hi
>
> Yes, but we fail to indicate to user space that connections may have been
> dropped. I doubt we can simply pretend the loss of power hasn't occured.
> Have you tested what happens if you go to S3 while eg. a file is transfered
> or audio played with your patch?

Hi Oliver,

Indeed, loss of power event should not be ignored.

Just tested file transferring. If there's no active connection,
everything goes fine. But if a file is transferring while going to S3,
bluetooth is not working after resume. Use applet to disable and
re-enable bluetooth makes it work again...

Wondering what is the right way to handle loss of power...

Regards,
Jesse