Re: [PATCH] hid: enable hid device to suspend/resume asynchronously

From: Jiri Kosina
Date: Fri Sep 25 2015 - 08:05:45 EST


On Thu, 24 Sep 2015, Fu, Zhonghui wrote:

> >> Enable hid device to suspend/resume asynchronously. This can improve
> >> system suspend/resume speed.
> > How well was this tested?
> >
> > Power management is notorious for not being really in excellent shape on
> > many HID devices.
> >
> > So I'd like to be careful.
> I were on leave these days, so sorry for late reply.
>
> This can reduce system suspend/resume time about 20ms, from 1030ms to
> 1010ms on ASUS T100TA machine. Although the improvement is not very
> significant, but this can let your parent/child device suspend/resume
> more asynchronously and take advantage of multicore to improve overall
> system suspend/resume speed.
>
> I have resent this patch with updated commit message - "[PATCH v2] hid:
> enable hid device to suspend/resume asynchronously".

Is there any reason why not enable this from userspace via sysfs instead,
based on whitelist on known-to-be-well-behaved devices, from udev?

I am really careful when it comes to enabling features like this
(especially given the state of PM support on some low-end devices)
globally.

Thanks,

--
Jiri Kosina
SUSE Labs

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