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

From: Oliver Neukum <[email-masked]>
Date: Wed, 23 Dec 2015 09:20:13 +0100

On Wed, 2015-12-23 at 03:31 +0000, Hayes Wang wrote:
> Oliver Neukum [mailto:[email-masked]]
> [...]
> > 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