Re: [PATCH v2] r8152: fix lockup when runtime PM is enabled

Oliver Neukum
2015-12-23T08:22:24Z

On Wed, 2015-12-23 at 03:31 +0000, Hayes Wang wrote:
> Oliver Neukum [mailto:oneukum@suse.com]
> [...]
> > It is clear to me that you cannot get away with using the same operation
> > for resume() and reset_resume() in your driver. It is fundamentally
> > impossible. Firmware cannot fix it.
>
> I would think how to fix it.
>
> > Sorry for the length of the explanation.
>
> Thanks for your response. I have some questions. What are the flows when
> the system resume follows a system suspend which follows a autosuspend?
> Are they as following?
>
> 1. suspend() with PMSG_IS_AUTO for autosuspned.
> 2. suspend() for system suspend.
> 3. resume() for system resume.
>
> And, should the device exist autosuspend before (2)?

No, step (2) does not exist. Calls to suspend() and [reset_]resume()
always balance. Usually a driver shouldn't care about system suspend.
The way the driver is currently coded will also fail for Port-Power Off.

Regards
Oliver