Re: Auto suspend not working on usb hid devices

[vichy <vichy.kuo@gmail.com>]

hi alan:

2015-01-11 23:53 GMT+08:00 Alan Stern <stern@rowland.harvard.edu>:
> On Sun, 11 Jan 2015, vichy wrote:
>
>> hi all:
>> I list below environment I have that autosuspend seems doesn't work on
>> my platform.
>> 1. kernel version 3.10.30
>> 2. compile kernel with CONFIG_PM_RUNTIME=y
>> 3. "echo 'rpm:rpm_suspend' > set_event"
>> 4. insert hid devices and "echo auto > /sys/bus/usb/devices/6-1/power/control"
>> 5. there is no any usb related runtime suspend output in trace.
>>
>> Did I miss any kernel configuration to let it work?
>> Or where is the proper debug entry I can check why rpm_suspend isn't
>> been called on my system?
>
> There are lots of reasons why a device might not be runtime suspended.
> There is no single debug entry that presents them.  Some information
> can be seen in the files in the device's /sys/.../power directory.

I found the power/runtime_usage = 2 when device plug in and do nothing.
Except update_autosuspend will increase runtime_usage, is there any
function will increase it when we did not enable runtime
suspend/resume?

Thanks for your kind help,