On 2015/8/24 15:38, Johannes Berg wrote: > 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? 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 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
