On Mon, 2015-08-24 at 11:45 +0800, Fu, Zhonghui wrote: > > On 2015/8/17 16:46, Arend van Spriel wrote: > > + Rafael > > > > On 08/17/2015 09:29 AM, Johannes Berg wrote: > > > On Mon, 2015-08-17 at 09:48 +0800, Fu, Zhonghui wrote: > > > > > > > > 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? thanks, johannes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
