On 2015/8/24 15:38, Johannes Berg wrote:

On Mon, 2015-08-24 at 11:45 +0800, Fu, Zhonghui wrote:

quoted

On 2015/8/17 16:46, Arend van Spriel wrote:

quoted

+ Rafael

On 08/17/2015 09:29 AM, Johannes Berg wrote:

quoted

On Mon, 2015-08-17 at 09:48 +0800, Fu, Zhonghui wrote:

quoted

The suspend/resume timing of wiphy device and related devices 
will be
ensured by their parent/child relationship. So, enabling wiphy 
device
to suspend/resume asynchronously does not change any 
 dependency. It
can only take advantage of multicore and improve system
suspend/resume speed.

You're going to have to explain that to me, because I don't see 
that.
All I see is that when looking at a device, if async is possible, 
it
gets added to an async work, and if async is not possible then it 
gets
done immediately. Even putting aside the question of whether or 
not
async is ordered or not (I don't know), if the wiphy is async and 
the
PCI (or other bus) device isn't, then it seems they could get 
handled
out of order, no? Or is there some magic code somewhere that I'm
missing that explicitly waits for the async of the parent/child
relationship?

This patch got me worried as well. Can't find the magic either. 
Maybe Rafael can give some hints here.

"dpm_wait_for_children" function will be invoked in 
"__device_suspend", "__device_suspend_late", and 
"__device_suspend_noirq" functions to synchronize the child 
relationship. "dpm_wait" function will be invoked in 
"device_resume_noirq", "device_resume_early", and "device_resume" 
functions to synchronize the parent relationship. If two devices have 
parent/child relationship, but different suspend/resume mode(sync or 
async), this will have no impact to PM timing order between them. 
Because all devices will use "__device_suspend", 
"__device_suspend_late" ... functions to complete their PM 
transition.

Ok, good point. For the unaware here, can you please resend with a
commit message amended with some of this information?

I take some leaves these days, so very sorry for late reply.

I have resent this patch with your advices - "[PATCH v2] net/wireless: enable wiphy device to suspend/resume asynchronously".


Thanks,
Zhonghui

thanks,
johannes